diff --git a/Benchmarks/Sources/Generated/JavaScript/BridgeJS.json b/Benchmarks/Sources/Generated/JavaScript/BridgeJS.json
index 95c4ac18e..b2c33ac01 100644
--- a/Benchmarks/Sources/Generated/JavaScript/BridgeJS.json
+++ b/Benchmarks/Sources/Generated/JavaScript/BridgeJS.json
@@ -2839,6 +2839,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "benchmarkHelperNoop",
             "parameters" : [
 
@@ -2850,6 +2855,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "benchmarkHelperNoopWithNumber",
             "parameters" : [
               {
@@ -2868,6 +2878,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "benchmarkRunner",
             "parameters" : [
               {
diff --git a/Examples/PlayBridgeJS/Sources/PlayBridgeJS/Generated/JavaScript/BridgeJS.json b/Examples/PlayBridgeJS/Sources/PlayBridgeJS/Generated/JavaScript/BridgeJS.json
index 60eb694ff..1a21916ee 100644
--- a/Examples/PlayBridgeJS/Sources/PlayBridgeJS/Generated/JavaScript/BridgeJS.json
+++ b/Examples/PlayBridgeJS/Sources/PlayBridgeJS/Generated/JavaScript/BridgeJS.json
@@ -242,6 +242,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "createTS2Swift",
             "parameters" : [
 
@@ -260,6 +265,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "convert",
                 "parameters" : [
                   {
diff --git a/Plugins/BridgeJS/Sources/BridgeJSBuildPlugin/BridgeJSBuildPlugin.swift b/Plugins/BridgeJS/Sources/BridgeJSBuildPlugin/BridgeJSBuildPlugin.swift
index 3cb6dc860..0236039d3 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSBuildPlugin/BridgeJSBuildPlugin.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSBuildPlugin/BridgeJSBuildPlugin.swift
@@ -20,9 +20,11 @@ struct BridgeJSBuildPlugin: BuildToolPlugin {
 
     private func createGenerateCommand(context: PluginContext, target: SwiftSourceModuleTarget) throws -> Command {
         let outputSwiftPath = context.pluginWorkDirectoryURL.appending(path: "BridgeJS.swift")
+        let outputMacrosSwiftPath = context.pluginWorkDirectoryURL.appending(path: "BridgeJS.Macros.swift")
 
         let inputSwiftFiles = target.sourceFiles.filter {
-            !$0.url.path.hasPrefix(context.pluginWorkDirectoryURL.path + "/")
+            $0.url.pathExtension == "swift"
+                && !$0.url.path.hasPrefix(context.pluginWorkDirectoryURL.path + "/")
         }
         .map(\.url)
 
@@ -42,6 +44,7 @@ struct BridgeJSBuildPlugin: BuildToolPlugin {
         inputFiles.append(contentsOf: pluginGeneratedSwiftFiles)
 
         let inputTSFile = target.directoryURL.appending(path: "bridge-js.d.ts")
+        let inputGlobalTSFile = target.directoryURL.appending(path: "bridge-js.global.d.ts")
         let tsconfigPath = context.package.directoryURL.appending(path: "tsconfig.json")
 
         var arguments: [String] = [
@@ -55,8 +58,16 @@ struct BridgeJSBuildPlugin: BuildToolPlugin {
             "--always-write", "true",
         ]
 
-        if FileManager.default.fileExists(atPath: inputTSFile.path) {
-            inputFiles.append(contentsOf: [inputTSFile, tsconfigPath])
+        let hasDts = FileManager.default.fileExists(atPath: inputTSFile.path)
+        let hasGlobalDts = FileManager.default.fileExists(atPath: inputGlobalTSFile.path)
+        if hasDts || hasGlobalDts {
+            if hasDts {
+                inputFiles.append(inputTSFile)
+            }
+            if hasGlobalDts {
+                inputFiles.append(inputGlobalTSFile)
+            }
+            inputFiles.append(tsconfigPath)
             arguments.append(contentsOf: [
                 "--project",
                 tsconfigPath.path,
@@ -71,7 +82,7 @@ struct BridgeJSBuildPlugin: BuildToolPlugin {
             executable: try context.tool(named: "BridgeJSTool").url,
             arguments: arguments,
             inputFiles: inputFiles,
-            outputFiles: [outputSwiftPath]
+            outputFiles: [outputSwiftPath, outputMacrosSwiftPath]
         )
     }
 }
diff --git a/Plugins/BridgeJS/Sources/BridgeJSCommandPlugin/BridgeJSCommandPlugin.swift b/Plugins/BridgeJS/Sources/BridgeJSCommandPlugin/BridgeJSCommandPlugin.swift
index 23fbae567..634720b89 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCommandPlugin/BridgeJSCommandPlugin.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCommandPlugin/BridgeJSCommandPlugin.swift
@@ -103,6 +103,7 @@ extension BridgeJSCommandPlugin.Context {
         let generatedDirectory = target.directoryURL.appending(path: "Generated")
 
         let bridgeDtsPath = target.directoryURL.appending(path: "bridge-js.d.ts")
+        let bridgeGlobalDtsPath = target.directoryURL.appending(path: "bridge-js.global.d.ts")
         let tsconfigPath = context.package.directoryURL.appending(path: "tsconfig.json")
 
         // Unified generate command
@@ -118,12 +119,16 @@ extension BridgeJSCommandPlugin.Context {
             options.verbose ? "true" : "false",
         ]
 
-        if FileManager.default.fileExists(atPath: bridgeDtsPath.path) {
+        let hasDts = FileManager.default.fileExists(atPath: bridgeDtsPath.path)
+        let hasGlobalDts = FileManager.default.fileExists(atPath: bridgeGlobalDtsPath.path)
+        if hasDts || hasGlobalDts {
             generateArguments.append(contentsOf: [
                 "--project",
                 tsconfigPath.path,
-                bridgeDtsPath.path,
             ])
+            if hasDts {
+                generateArguments.append(bridgeDtsPath.path)
+            }
         }
 
         generateArguments.append(
diff --git a/Plugins/BridgeJS/Sources/BridgeJSCore/ClosureCodegen.swift b/Plugins/BridgeJS/Sources/BridgeJSCore/ClosureCodegen.swift
index 142050f56..fcf71611b 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCore/ClosureCodegen.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCore/ClosureCodegen.swift
@@ -12,7 +12,10 @@ public struct ClosureCodegen {
     public init() {}
 
     private func swiftClosureType(for signature: ClosureSignature) -> String {
-        let closureParams = signature.parameters.map { "\($0.closureSwiftType)" }.joined(separator: ", ")
+        let sendingPrefix = signature.sendingParameters ? "sending " : ""
+        let closureParams = signature.parameters.map { "\(sendingPrefix)\($0.closureSwiftType)" }.joined(
+            separator: ", "
+        )
         let swiftEffects = (signature.isAsync ? " async" : "") + (signature.isThrows ? " throws" : "")
         let swiftReturnType = signature.returnType.closureSwiftType
         return "(\(closureParams))\(swiftEffects) -> \(swiftReturnType)"
@@ -188,7 +191,78 @@ public struct ClosureCodegen {
         let collector = ClosureSignatureCollectorVisitor()
         var walker = BridgeTypeWalker(visitor: collector)
         walker.walk(skeleton)
-        let closureSignatures = walker.visitor.signatures
+        var closureSignatures = walker.visitor.signatures
+
+        // When async imports exist, inject closure signatures for the typed resolve
+        // and reject callbacks used by _bjs_awaitPromise.
+        // - Reject always uses (sending JSValue) -> Void
+        // - Resolve uses a typed closure matching the return type (or () -> Void for void)
+        // All async callback closures use `sending` parameters so values can be
+        // transferred through the checked continuation without Sendable constraints.
+        if let imported = skeleton.imported {
+            for file in imported.children {
+                for function in file.functions where function.effects.isAsync {
+                    // Reject callback
+                    closureSignatures.insert(
+                        ClosureSignature(
+                            parameters: [.jsValue],
+                            returnType: .void,
+                            moduleName: skeleton.moduleName,
+                            sendingParameters: true
+                        )
+                    )
+                    // Resolve callback (typed per return type)
+                    if function.returnType == .void {
+                        closureSignatures.insert(
+                            ClosureSignature(
+                                parameters: [],
+                                returnType: .void,
+                                moduleName: skeleton.moduleName
+                            )
+                        )
+                    } else {
+                        closureSignatures.insert(
+                            ClosureSignature(
+                                parameters: [function.returnType],
+                                returnType: .void,
+                                moduleName: skeleton.moduleName,
+                                sendingParameters: true
+                            )
+                        )
+                    }
+                }
+                for type in file.types {
+                    for method in type.methods where method.effects.isAsync {
+                        closureSignatures.insert(
+                            ClosureSignature(
+                                parameters: [.jsValue],
+                                returnType: .void,
+                                moduleName: skeleton.moduleName,
+                                sendingParameters: true
+                            )
+                        )
+                        if method.returnType == .void {
+                            closureSignatures.insert(
+                                ClosureSignature(
+                                    parameters: [],
+                                    returnType: .void,
+                                    moduleName: skeleton.moduleName
+                                )
+                            )
+                        } else {
+                            closureSignatures.insert(
+                                ClosureSignature(
+                                    parameters: [method.returnType],
+                                    returnType: .void,
+                                    moduleName: skeleton.moduleName,
+                                    sendingParameters: true
+                                )
+                            )
+                        }
+                    }
+                }
+            }
+        }
 
         guard !closureSignatures.isEmpty else { return nil }
 
diff --git a/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift b/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift
index 1d1fe3aa9..d709dd190 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCore/ImportTS.swift
@@ -212,7 +212,16 @@ public struct ImportTS {
             }
         }
 
-        func call() throws {
+        /// Prepends `resolveRef: Int32, rejectRef: Int32` parameters to the ABI parameter list.
+        ///
+        /// Used for async imports where the JS side receives closure-backed
+        /// resolve/reject callbacks as object references.
+        func prependClosureCallbackParams() {
+            abiParameterSignatures.insert(contentsOf: [("resolveRef", .i32), ("rejectRef", .i32)], at: 0)
+            abiParameterForwardings.insert(contentsOf: ["resolveRef", "rejectRef"], at: 0)
+        }
+
+        func call(skipExceptionCheck: Bool = false) throws {
             for stmt in stackLoweringStmts {
                 body.write(stmt.description)
             }
@@ -243,8 +252,9 @@ public struct ImportTS {
                 }
             }
 
-            // Add exception check for ImportTS context
-            if context == .importTS {
+            // Add exception check for ImportTS context (skipped for async, where
+            // errors are funneled through the JS-side reject path)
+            if !skipExceptionCheck && context == .importTS {
                 body.write("if let error = _swift_js_take_exception() { throw error }")
             }
         }
@@ -278,6 +288,41 @@ public struct ImportTS {
             }
         }
 
+        func liftAsyncReturnValue(originalReturnType: BridgeType) {
+            // For async imports, the extern function takes leading `resolveRef: Int32, rejectRef: Int32`
+            // and returns void. The JS side calls the resolve/reject closures when the Promise settles.
+            // The resolve closure is typed to match the return type, so the ABI conversion is handled
+            // by the existing closure codegen infrastructure — no manual JSValue-to-type switch needed.
+            abiReturnType = nil
+
+            // Wrap the existing body (parameter lowering + extern call) in _bjs_awaitPromise
+            let innerBody = body
+            body = CodeFragmentPrinter()
+
+            let rejectFactory = "makeRejectClosure: { JSTypedClosure<(sending JSValue) -> Void>($0) }"
+            if originalReturnType == .void {
+                let resolveFactory = "makeResolveClosure: { JSTypedClosure<() -> Void>($0) }"
+                body.write(
+                    "try await _bjs_awaitPromise(\(resolveFactory), \(rejectFactory)) { resolveRef, rejectRef in"
+                )
+            } else {
+                let resolveSwiftType = originalReturnType.closureSwiftType
+                let resolveFactory =
+                    "makeResolveClosure: { JSTypedClosure<(sending \(resolveSwiftType)) -> Void>($0) }"
+                body.write(
+                    "let resolved = try await _bjs_awaitPromise(\(resolveFactory), \(rejectFactory)) { resolveRef, rejectRef in"
+                )
+            }
+            body.indent {
+                body.write(lines: innerBody.lines)
+            }
+            body.write("}")
+
+            if originalReturnType != .void {
+                body.write("return resolved")
+            }
+        }
+
         func assignThis(returnType: BridgeType) {
             guard case .jsObject = returnType else {
                 preconditionFailure("assignThis can only be called with a jsObject return type")
@@ -299,9 +344,13 @@ public struct ImportTS {
             return "\(raw: printer.lines.joined(separator: "\n"))"
         }
 
-        func renderThunkDecl(name: String, parameters: [Parameter], returnType: BridgeType) -> DeclSyntax {
+        func renderThunkDecl(
+            name: String,
+            parameters: [Parameter],
+            returnType: BridgeType,
+            effects: Effects = Effects(isAsync: false, isThrows: true)
+        ) -> DeclSyntax {
             let printer = CodeFragmentPrinter()
-            let effects = Effects(isAsync: false, isThrows: true)
             let signature = SwiftSignatureBuilder.buildFunctionSignature(
                 parameters: parameters,
                 returnType: returnType,
@@ -359,22 +408,33 @@ public struct ImportTS {
         _ function: ImportedFunctionSkeleton,
         topLevelDecls: inout [DeclSyntax]
     ) throws -> [DeclSyntax] {
+        // For async functions, the extern returns void (the JS side resolves/rejects
+        // via continuation callbacks). For sync functions, use the actual return type.
+        let abiReturnType: BridgeType = function.effects.isAsync ? .void : function.returnType
         let builder = try CallJSEmission(
             moduleName: moduleName,
             abiName: function.abiName(context: nil),
-            returnType: function.returnType
+            returnType: abiReturnType
         )
+        if function.effects.isAsync {
+            builder.prependClosureCallbackParams()
+        }
         for param in function.parameters {
             try builder.lowerParameter(param: param)
         }
-        try builder.call()
-        try builder.liftReturnValue()
+        try builder.call(skipExceptionCheck: function.effects.isAsync)
+        if function.effects.isAsync {
+            builder.liftAsyncReturnValue(originalReturnType: function.returnType)
+        } else {
+            try builder.liftReturnValue()
+        }
         topLevelDecls.append(builder.renderImportDecl())
         return [
             builder.renderThunkDecl(
                 name: Self.thunkName(function: function),
                 parameters: function.parameters,
-                returnType: function.returnType
+                returnType: function.returnType,
+                effects: function.effects
             )
             .with(\.leadingTrivia, Self.renderDocumentation(documentation: function.documentation))
         ]
@@ -385,41 +445,56 @@ public struct ImportTS {
         var decls: [DeclSyntax] = []
 
         func renderMethod(method: ImportedFunctionSkeleton) throws -> [DeclSyntax] {
+            let abiReturnType: BridgeType = method.effects.isAsync ? .void : method.returnType
             let builder = try CallJSEmission(
                 moduleName: moduleName,
                 abiName: method.abiName(context: type),
-                returnType: method.returnType
+                returnType: abiReturnType
             )
+            if method.effects.isAsync {
+                builder.prependClosureCallbackParams()
+            }
             try builder.lowerParameter(param: selfParameter)
             for param in method.parameters {
                 try builder.lowerParameter(param: param)
             }
-            try builder.call()
-            try builder.liftReturnValue()
+            try builder.call(skipExceptionCheck: method.effects.isAsync)
+            if method.effects.isAsync {
+                builder.liftAsyncReturnValue(originalReturnType: method.returnType)
+            } else {
+                try builder.liftReturnValue()
+            }
             topLevelDecls.append(builder.renderImportDecl())
             return [
                 builder.renderThunkDecl(
                     name: Self.thunkName(type: type, method: method),
                     parameters: [selfParameter] + method.parameters,
-                    returnType: method.returnType
+                    returnType: method.returnType,
+                    effects: method.effects
                 )
             ]
         }
 
         func renderStaticMethod(method: ImportedFunctionSkeleton) throws -> [DeclSyntax] {
             let abiName = method.abiName(context: type, operation: "static")
-            let builder = try CallJSEmission(moduleName: moduleName, abiName: abiName, returnType: method.returnType)
+            let abiReturnType: BridgeType = method.effects.isAsync ? .jsObject(nil) : method.returnType
+            let builder = try CallJSEmission(moduleName: moduleName, abiName: abiName, returnType: abiReturnType)
             for param in method.parameters {
                 try builder.lowerParameter(param: param)
             }
             try builder.call()
-            try builder.liftReturnValue()
+            if method.effects.isAsync {
+                builder.liftAsyncReturnValue(originalReturnType: method.returnType)
+            } else {
+                try builder.liftReturnValue()
+            }
             topLevelDecls.append(builder.renderImportDecl())
             return [
                 builder.renderThunkDecl(
                     name: Self.thunkName(type: type, method: method),
                     parameters: method.parameters,
-                    returnType: method.returnType
+                    returnType: method.returnType,
+                    effects: method.effects
                 )
             ]
         }
diff --git a/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift b/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift
index 482b1fff5..7b7c6ca30 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSCore/SwiftToSkeleton.swift
@@ -2137,7 +2137,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
         let valueType: BridgeType
     }
 
-    /// Validates effects (throws required, async not supported)
+    /// Validates effects (throws required, async only supported for @JSFunction)
     private func validateEffects(
         _ effects: FunctionEffectSpecifiersSyntax?,
         node: some SyntaxProtocol,
@@ -2153,7 +2153,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
             )
             return nil
         }
-        if effects.isAsync {
+        if effects.isAsync && attributeName != "JSFunction" {
             errors.append(
                 DiagnosticError(
                     node: node,
@@ -2490,7 +2490,12 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
         _ jsFunction: AttributeSyntax,
         _ node: FunctionDeclSyntax,
     ) -> ImportedFunctionSkeleton? {
-        guard validateEffects(node.signature.effectSpecifiers, node: node, attributeName: "JSFunction") != nil
+        guard
+            let effects = validateEffects(
+                node.signature.effectSpecifiers,
+                node: node,
+                attributeName: "JSFunction"
+            )
         else {
             return nil
         }
@@ -2516,6 +2521,7 @@ private final class ImportSwiftMacrosAPICollector: SyntaxAnyVisitor {
             from: from,
             parameters: parameters,
             returnType: returnType,
+            effects: effects,
             documentation: nil
         )
     }
diff --git a/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift b/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift
index f69a4b266..573693e4f 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSLink/BridgeJSLink.swift
@@ -639,7 +639,75 @@ public struct BridgeJSLink {
                     let collector = ClosureSignatureCollectorVisitor()
                     var walker = BridgeTypeWalker(visitor: collector)
                     walker.walk(unified)
-                    let closureSignatures = walker.visitor.signatures
+                    var closureSignatures = walker.visitor.signatures
+
+                    // Inject closure signatures for async import resolve/reject callbacks.
+                    // All use sendingParameters: true so values can be transferred
+                    // through checked continuations without Sendable constraints.
+                    if let imported = unified.imported {
+                        for file in imported.children {
+                            for function in file.functions where function.effects.isAsync {
+                                // Reject callback
+                                closureSignatures.insert(
+                                    ClosureSignature(
+                                        parameters: [.jsValue],
+                                        returnType: .void,
+                                        moduleName: moduleName,
+                                        sendingParameters: true
+                                    )
+                                )
+                                // Resolve callback (typed per return type)
+                                if function.returnType == .void {
+                                    closureSignatures.insert(
+                                        ClosureSignature(
+                                            parameters: [],
+                                            returnType: .void,
+                                            moduleName: moduleName
+                                        )
+                                    )
+                                } else {
+                                    closureSignatures.insert(
+                                        ClosureSignature(
+                                            parameters: [function.returnType],
+                                            returnType: .void,
+                                            moduleName: moduleName,
+                                            sendingParameters: true
+                                        )
+                                    )
+                                }
+                            }
+                            for type in file.types {
+                                for method in type.methods where method.effects.isAsync {
+                                    closureSignatures.insert(
+                                        ClosureSignature(
+                                            parameters: [.jsValue],
+                                            returnType: .void,
+                                            moduleName: moduleName,
+                                            sendingParameters: true
+                                        )
+                                    )
+                                    if method.returnType == .void {
+                                        closureSignatures.insert(
+                                            ClosureSignature(
+                                                parameters: [],
+                                                returnType: .void,
+                                                moduleName: moduleName
+                                            )
+                                        )
+                                    } else {
+                                        closureSignatures.insert(
+                                            ClosureSignature(
+                                                parameters: [method.returnType],
+                                                returnType: .void,
+                                                moduleName: moduleName,
+                                                sendingParameters: true
+                                            )
+                                        )
+                                    }
+                                }
+                            }
+                        }
+                    }
 
                     guard !closureSignatures.isEmpty else { continue }
 
@@ -1233,7 +1301,7 @@ public struct BridgeJSLink {
                     for method in type.methods {
                         let methodName = method.jsName ?? method.name
                         let methodSignature =
-                            "\(renderTSPropertyName(methodName))\(renderTSSignature(parameters: method.parameters, returnType: method.returnType, effects: Effects(isAsync: false, isThrows: false)));"
+                            "\(renderTSPropertyName(methodName))\(renderTSSignature(parameters: method.parameters, returnType: method.returnType, effects: method.effects));"
                         printer.write(methodSignature)
                     }
 
@@ -2232,6 +2300,34 @@ extension BridgeJSLink {
             return printer.lines
         }
 
+        /// Generates the call expression for an async import.
+        ///
+        /// Chains `.then(resolve, reject)` directly on the returned Promise.
+        func callAsync(name: String, fromObjectExpr: String) {
+            let calleeExpr = Self.propertyAccessExpr(objectExpr: fromObjectExpr, propertyName: name)
+            let callExpr = "\(calleeExpr)(\(parameterForwardings.joined(separator: ", ")))"
+            body.write("\(callExpr).then(resolve, reject);")
+        }
+
+        /// Renders an async import function with resolve/reject closure refs.
+        ///
+        /// The generated function takes `resolveRef` and `rejectRef` as the first parameters,
+        /// looks up the resolve/reject closures from memory, and executes the body which
+        /// chains `.then(resolve, reject)` on the import's returned Promise.
+        func renderAsyncFunction(name: String?) -> [String] {
+            let printer = CodeFragmentPrinter()
+            let allParams = ["resolveRef", "rejectRef"] + parameterNames
+            printer.write("function\(name.map { " \($0)" } ?? "")(\(allParams.joined(separator: ", "))) {")
+            printer.indent {
+                let s = JSGlueVariableScope.reservedSwift
+                printer.write("const resolve = \(s).memory.getObject(resolveRef);")
+                printer.write("const reject = \(s).memory.getObject(rejectRef);")
+                printer.write(contentsOf: body)
+            }
+            printer.write("}")
+            return printer.lines
+        }
+
         func call(name: String, fromObjectExpr: String, returnType: BridgeType) throws -> String? {
             let calleeExpr = Self.propertyAccessExpr(objectExpr: fromObjectExpr, propertyName: name)
             return try self.call(calleeExpr: calleeExpr, returnType: returnType)
@@ -2285,6 +2381,14 @@ extension BridgeJSLink {
             )
         }
 
+        /// Generates an async method call with resolve/reject closure refs.
+        func callAsyncMethod(name: String) {
+            let objectExpr = "\(JSGlueVariableScope.reservedSwift).memory.getObject(self)"
+            let calleeExpr = Self.propertyAccessExpr(objectExpr: objectExpr, propertyName: name)
+            let callExpr = "\(calleeExpr)(\(parameterForwardings.joined(separator: ", ")))"
+            body.write("\(callExpr).then(resolve, reject);")
+        }
+
         func callStaticMethod(on objectExpr: String, name: String, returnType: BridgeType) throws -> String? {
             let calleeExpr = Self.propertyAccessExpr(objectExpr: objectExpr, propertyName: name)
             return try call(
@@ -3124,21 +3228,31 @@ extension BridgeJSLink {
         }
         let jsName = function.jsName ?? function.name
         let importRootExpr = function.from == .global ? "globalThis" : "imports"
-        let returnExpr = try thunkBuilder.call(
-            name: jsName,
-            fromObjectExpr: importRootExpr,
-            returnType: function.returnType
-        )
-        let funcLines = thunkBuilder.renderFunction(
-            name: function.abiName(context: nil),
-            returnExpr: returnExpr,
-            returnType: function.returnType
-        )
-        let effects = Effects(isAsync: false, isThrows: false)
+
+        let funcLines: [String]
+        if function.effects.isAsync {
+            // For async functions, use the continuation-pointer pattern.
+            // The generated function takes continuationPtr as first param,
+            // calls the import, attaches .then/.catch on the returned Promise,
+            // and calls resolve/reject continuations.
+            thunkBuilder.callAsync(name: jsName, fromObjectExpr: importRootExpr)
+            funcLines = thunkBuilder.renderAsyncFunction(name: function.abiName(context: nil))
+        } else {
+            let returnExpr = try thunkBuilder.call(
+                name: jsName,
+                fromObjectExpr: importRootExpr,
+                returnType: function.returnType
+            )
+            funcLines = thunkBuilder.renderFunction(
+                name: function.abiName(context: nil),
+                returnExpr: returnExpr,
+                returnType: function.returnType
+            )
+        }
         if function.from == nil {
             importObjectBuilder.appendDts(
                 [
-                    "\(renderTSPropertyName(jsName))\(renderTSSignature(parameters: function.parameters, returnType: function.returnType, effects: effects));"
+                    "\(renderTSPropertyName(jsName))\(renderTSSignature(parameters: function.parameters, returnType: function.returnType, effects: function.effects));"
                 ]
             )
         }
@@ -3337,12 +3451,22 @@ extension BridgeJSLink {
         for param in method.parameters {
             try thunkBuilder.liftParameter(param: param)
         }
-        let returnExpr = try thunkBuilder.callMethod(name: method.jsName ?? method.name, returnType: method.returnType)
-        let funcLines = thunkBuilder.renderFunction(
-            name: method.abiName(context: context),
-            returnExpr: returnExpr,
-            returnType: method.returnType
-        )
+
+        let funcLines: [String]
+        if method.effects.isAsync {
+            thunkBuilder.callAsyncMethod(name: method.jsName ?? method.name)
+            funcLines = thunkBuilder.renderAsyncFunction(name: method.abiName(context: context))
+        } else {
+            let returnExpr = try thunkBuilder.callMethod(
+                name: method.jsName ?? method.name,
+                returnType: method.returnType
+            )
+            funcLines = thunkBuilder.renderFunction(
+                name: method.abiName(context: context),
+                returnExpr: returnExpr,
+                returnType: method.returnType
+            )
+        }
         return (funcLines, [])
     }
 
diff --git a/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift b/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift
index 1f03e09ba..f61f7e2cf 100644
--- a/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift
+++ b/Plugins/BridgeJS/Sources/BridgeJSSkeleton/BridgeJSSkeleton.swift
@@ -101,24 +101,31 @@ public struct ClosureSignature: Codable, Equatable, Hashable, Sendable {
     public let isAsync: Bool
     public let isThrows: Bool
     public let moduleName: String
+    /// When true, closure parameters are annotated with `sending` in Swift.
+    /// Used for async Promise resolve/reject callbacks where values are
+    /// transferred through a continuation.
+    public let sendingParameters: Bool
 
     public init(
         parameters: [BridgeType],
         returnType: BridgeType,
         moduleName: String,
         isAsync: Bool = false,
-        isThrows: Bool = false
+        isThrows: Bool = false,
+        sendingParameters: Bool = false
     ) {
         self.parameters = parameters
         self.returnType = returnType
         self.moduleName = moduleName
         self.isAsync = isAsync
         self.isThrows = isThrows
+        self.sendingParameters = sendingParameters
         let paramPart =
             parameters.isEmpty
             ? "y"
             : parameters.map { $0.mangleTypeName }.joined()
-        let signaturePart = "\(paramPart)_\(returnType.mangleTypeName)"
+        let sendingPart = sendingParameters ? "s" : ""
+        let signaturePart = "\(sendingPart)\(paramPart)_\(returnType.mangleTypeName)"
         self.mangleName = "\(moduleName.count)\(moduleName)\(signaturePart)"
     }
 }
@@ -923,6 +930,7 @@ public struct ImportedFunctionSkeleton: Codable {
     public let from: JSImportFrom?
     public let parameters: [Parameter]
     public let returnType: BridgeType
+    public let effects: Effects
     public let documentation: String?
 
     public init(
@@ -931,6 +939,7 @@ public struct ImportedFunctionSkeleton: Codable {
         from: JSImportFrom? = nil,
         parameters: [Parameter],
         returnType: BridgeType,
+        effects: Effects = Effects(isAsync: false, isThrows: true),
         documentation: String? = nil
     ) {
         self.name = name
@@ -938,6 +947,7 @@ public struct ImportedFunctionSkeleton: Codable {
         self.from = from
         self.parameters = parameters
         self.returnType = returnType
+        self.effects = effects
         self.documentation = documentation
     }
 
diff --git a/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/src/processor.js b/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/src/processor.js
index 9617a5261..91a42a9ef 100644
--- a/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/src/processor.js
+++ b/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/src/processor.js
@@ -313,8 +313,8 @@ export class TypeProcessor {
                 const parameters = signature.getParameters();
                 const parameterNameMap = this.buildParameterNameMap(parameters);
                 const params = this.renderParameters(parameters, decl);
-                const returnType = this.visitType(signature.getReturnType(), decl);
-                const effects = this.renderEffects({ isAsync: false });
+                const { returnType, isAsync } = this.unwrapPromiseReturnType(signature.getReturnType(), decl);
+                const effects = this.renderEffects({ isAsync });
                 const annotation = this.renderMacroAnnotation("JSFunction", args);
 
                 this.emitDocComment(decl, { indent: "", parameterNameMap });
@@ -581,8 +581,8 @@ export class TypeProcessor {
         const parameters = signature.getParameters();
         const parameterNameMap = this.buildParameterNameMap(parameters);
         const params = this.renderParameters(parameters, node);
-        const returnType = this.visitType(signature.getReturnType(), node);
-        const effects = this.renderEffects({ isAsync: false });
+        const { returnType, isAsync } = this.unwrapPromiseReturnType(signature.getReturnType(), node);
+        const effects = this.renderEffects({ isAsync });
         const swiftFuncName = this.renderIdentifier(swiftName);
 
         this.emitDocComment(node, { parameterNameMap });
@@ -1210,8 +1210,8 @@ export class TypeProcessor {
         const parameters = signature.getParameters();
         const parameterNameMap = this.buildParameterNameMap(parameters);
         const params = this.renderParameters(parameters, node);
-        const returnType = this.visitType(signature.getReturnType(), node);
-        const effects = this.renderEffects({ isAsync: false });
+        const { returnType, isAsync } = this.unwrapPromiseReturnType(signature.getReturnType(), node);
+        const effects = this.renderEffects({ isAsync });
         const swiftMethodName = this.renderIdentifier(swiftName);
         const isStatic = node.modifiers?.some(
             (modifier) => modifier.kind === ts.SyntaxKind.StaticKeyword
@@ -1281,6 +1281,27 @@ export class TypeProcessor {
         return parts.join(" ");
     }
 
+    /**
+     * Check if a type is Promise<T> and extract the return type and async flag.
+     * @param {ts.Type} type - The return type to check
+     * @param {ts.Node} node - The node for type visiting context
+     * @returns {{ returnType: string, isAsync: boolean }}
+     * @private
+     */
+    unwrapPromiseReturnType(type, node) {
+        if (isTypeReference(type)) {
+            const symbol = type.target?.getSymbol();
+            if (symbol?.name === "Promise") {
+                const typeArgs = this.checker.getTypeArguments(/** @type {ts.TypeReference} */ (type));
+                const innerType = typeArgs && typeArgs.length > 0
+                    ? this.visitType(typeArgs[0], node)
+                    : "Void";
+                return { returnType: innerType, isAsync: true };
+            }
+        }
+        return { returnType: this.visitType(type, node), isAsync: false };
+    }
+
     /**
      * @param {ts.Node} node
      * @returns {boolean}
diff --git a/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/test/__snapshots__/ts2swift.test.js.snap b/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/test/__snapshots__/ts2swift.test.js.snap
index 4122f4148..643ac8441 100644
--- a/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/test/__snapshots__/ts2swift.test.js.snap
+++ b/Plugins/BridgeJS/Sources/TS2Swift/JavaScript/test/__snapshots__/ts2swift.test.js.snap
@@ -32,19 +32,19 @@ exports[`ts2swift > snapshots Swift output for Async.d.ts > Async 1`] = `
 
 @_spi(BridgeJS) import JavaScriptKit
 
-@JSFunction func asyncReturnVoid() throws(JSException) -> JSPromise
+@JSFunction func asyncReturnVoid() async throws(JSException) -> Void
 
-@JSFunction func asyncRoundTripInt(_ v: Double) throws(JSException) -> JSPromise
+@JSFunction func asyncRoundTripInt(_ v: Double) async throws(JSException) -> Double
 
-@JSFunction func asyncRoundTripString(_ v: String) throws(JSException) -> JSPromise
+@JSFunction func asyncRoundTripString(_ v: String) async throws(JSException) -> String
 
-@JSFunction func asyncRoundTripBool(_ v: Bool) throws(JSException) -> JSPromise
+@JSFunction func asyncRoundTripBool(_ v: Bool) async throws(JSException) -> Bool
 
-@JSFunction func asyncRoundTripFloat(_ v: Double) throws(JSException) -> JSPromise
+@JSFunction func asyncRoundTripFloat(_ v: Double) async throws(JSException) -> Double
 
-@JSFunction func asyncRoundTripDouble(_ v: Double) throws(JSException) -> JSPromise
+@JSFunction func asyncRoundTripDouble(_ v: Double) async throws(JSException) -> Double
 
-@JSFunction func asyncRoundTripJSObject(_ v: JSValue) throws(JSException) -> JSPromise
+@JSFunction func asyncRoundTripJSObject(_ v: JSValue) async throws(JSException) -> JSValue
 "
 `;
 
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/AsyncImport.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/AsyncImport.swift
new file mode 100644
index 000000000..02563cbdf
--- /dev/null
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/Inputs/MacroSwift/AsyncImport.swift
@@ -0,0 +1,6 @@
+@JSFunction func asyncReturnVoid() async throws(JSException)
+@JSFunction func asyncRoundTripInt(_ v: Int) async throws(JSException) -> Int
+@JSFunction func asyncRoundTripString(_ v: String) async throws(JSException) -> String
+@JSFunction func asyncRoundTripBool(_ v: Bool) async throws(JSException) -> Bool
+@JSFunction func asyncRoundTripDouble(_ v: Double) async throws(JSException) -> Double
+@JSFunction func asyncRoundTripJSObject(_ v: JSObject) async throws(JSException) -> JSObject
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ArrayTypes.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ArrayTypes.json
index 3664fa339..d071d8c52 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ArrayTypes.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ArrayTypes.json
@@ -1331,6 +1331,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "checkArray",
             "parameters" : [
               {
@@ -1349,6 +1354,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "checkArrayWithLength",
             "parameters" : [
               {
@@ -1375,6 +1385,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "importProcessNumbers",
             "parameters" : [
               {
@@ -1397,6 +1412,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "importGetNumbers",
             "parameters" : [
 
@@ -1412,6 +1432,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "importTransformNumbers",
             "parameters" : [
               {
@@ -1438,6 +1463,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "importProcessStrings",
             "parameters" : [
               {
@@ -1464,6 +1494,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "importProcessBooleans",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/AsyncImport.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/AsyncImport.json
new file mode 100644
index 000000000..263578d20
--- /dev/null
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/AsyncImport.json
@@ -0,0 +1,151 @@
+{
+  "imported" : {
+    "children" : [
+      {
+        "functions" : [
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "asyncReturnVoid",
+            "parameters" : [
+
+            ],
+            "returnType" : {
+              "void" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "asyncRoundTripInt",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "integer" : {
+                    "_0" : {
+                      "isSigned" : true,
+                      "width" : "word"
+                    }
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "integer" : {
+                "_0" : {
+                  "isSigned" : true,
+                  "width" : "word"
+                }
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "asyncRoundTripString",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "string" : {
+
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "string" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "asyncRoundTripBool",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "bool" : {
+
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "bool" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "asyncRoundTripDouble",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "double" : {
+
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "double" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "asyncRoundTripJSObject",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "jsObject" : {
+
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "jsObject" : {
+
+              }
+            }
+          }
+        ],
+        "types" : [
+
+        ]
+      }
+    ]
+  },
+  "moduleName" : "TestModule"
+}
\ No newline at end of file
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/AsyncImport.swift b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/AsyncImport.swift
new file mode 100644
index 000000000..7a60bc6b7
--- /dev/null
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/AsyncImport.swift
@@ -0,0 +1,569 @@
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_TestModule_10TestModules7JSValueV_y")
+fileprivate func invoke_js_callback_TestModule_10TestModules7JSValueV_y_extern(_ callback: Int32, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void
+#else
+fileprivate func invoke_js_callback_TestModule_10TestModules7JSValueV_y_extern(_ callback: Int32, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_TestModule_10TestModules7JSValueV_y(_ callback: Int32, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void {
+    return invoke_js_callback_TestModule_10TestModules7JSValueV_y_extern(callback, param0Kind, param0Payload1, param0Payload2)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_TestModule_10TestModules7JSValueV_y")
+fileprivate func make_swift_closure_TestModule_10TestModules7JSValueV_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_TestModule_10TestModules7JSValueV_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_TestModule_10TestModules7JSValueV_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_TestModule_10TestModules7JSValueV_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_10TestModules7JSValueV_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending JSValue) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let (param0Kind, param0Payload1, param0Payload2) = param0.bridgeJSLowerParameter()
+            invoke_js_callback_TestModule_10TestModules7JSValueV_y(callbackValue, param0Kind, param0Payload1, param0Payload2)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending JSValue) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending JSValue) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_TestModule_10TestModules7JSValueV_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_TestModule_10TestModules7JSValueV_y")
+@_cdecl("invoke_swift_closure_TestModule_10TestModules7JSValueV_y")
+public func _invoke_swift_closure_TestModule_10TestModules7JSValueV_y(_ boxPtr: UnsafeMutableRawPointer, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending JSValue) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(JSValue.bridgeJSLiftParameter(param0Kind, param0Payload1, param0Payload2))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_TestModule_10TestModules8JSObjectC_y")
+fileprivate func invoke_js_callback_TestModule_10TestModules8JSObjectC_y_extern(_ callback: Int32, _ param0: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_TestModule_10TestModules8JSObjectC_y_extern(_ callback: Int32, _ param0: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_TestModule_10TestModules8JSObjectC_y(_ callback: Int32, _ param0: Int32) -> Void {
+    return invoke_js_callback_TestModule_10TestModules8JSObjectC_y_extern(callback, param0)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_TestModule_10TestModules8JSObjectC_y")
+fileprivate func make_swift_closure_TestModule_10TestModules8JSObjectC_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_TestModule_10TestModules8JSObjectC_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_TestModule_10TestModules8JSObjectC_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_TestModule_10TestModules8JSObjectC_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_10TestModules8JSObjectC_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending JSObject) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let param0Value = param0.bridgeJSLowerParameter()
+            invoke_js_callback_TestModule_10TestModules8JSObjectC_y(callbackValue, param0Value)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending JSObject) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending JSObject) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_TestModule_10TestModules8JSObjectC_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_TestModule_10TestModules8JSObjectC_y")
+@_cdecl("invoke_swift_closure_TestModule_10TestModules8JSObjectC_y")
+public func _invoke_swift_closure_TestModule_10TestModules8JSObjectC_y(_ boxPtr: UnsafeMutableRawPointer, _ param0: Int32) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending JSObject) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(JSObject.bridgeJSLiftParameter(param0))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_TestModule_10TestModulesSS_y")
+fileprivate func invoke_js_callback_TestModule_10TestModulesSS_y_extern(_ callback: Int32, _ param0Bytes: Int32, _ param0Length: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_TestModule_10TestModulesSS_y_extern(_ callback: Int32, _ param0Bytes: Int32, _ param0Length: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_TestModule_10TestModulesSS_y(_ callback: Int32, _ param0Bytes: Int32, _ param0Length: Int32) -> Void {
+    return invoke_js_callback_TestModule_10TestModulesSS_y_extern(callback, param0Bytes, param0Length)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_TestModule_10TestModulesSS_y")
+fileprivate func make_swift_closure_TestModule_10TestModulesSS_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_TestModule_10TestModulesSS_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_TestModule_10TestModulesSS_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_TestModule_10TestModulesSS_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_10TestModulesSS_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending String) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            param0.bridgeJSWithLoweredParameter { (param0Bytes, param0Length) in
+                invoke_js_callback_TestModule_10TestModulesSS_y(callbackValue, param0Bytes, param0Length)
+            }
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending String) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending String) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_TestModule_10TestModulesSS_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_TestModule_10TestModulesSS_y")
+@_cdecl("invoke_swift_closure_TestModule_10TestModulesSS_y")
+public func _invoke_swift_closure_TestModule_10TestModulesSS_y(_ boxPtr: UnsafeMutableRawPointer, _ param0Bytes: Int32, _ param0Length: Int32) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending String) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(String.bridgeJSLiftParameter(param0Bytes, param0Length))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_TestModule_10TestModulesSb_y")
+fileprivate func invoke_js_callback_TestModule_10TestModulesSb_y_extern(_ callback: Int32, _ param0: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_TestModule_10TestModulesSb_y_extern(_ callback: Int32, _ param0: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_TestModule_10TestModulesSb_y(_ callback: Int32, _ param0: Int32) -> Void {
+    return invoke_js_callback_TestModule_10TestModulesSb_y_extern(callback, param0)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_TestModule_10TestModulesSb_y")
+fileprivate func make_swift_closure_TestModule_10TestModulesSb_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_TestModule_10TestModulesSb_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_TestModule_10TestModulesSb_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_TestModule_10TestModulesSb_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_10TestModulesSb_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending Bool) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let param0Value = param0.bridgeJSLowerParameter()
+            invoke_js_callback_TestModule_10TestModulesSb_y(callbackValue, param0Value)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending Bool) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending Bool) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_TestModule_10TestModulesSb_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_TestModule_10TestModulesSb_y")
+@_cdecl("invoke_swift_closure_TestModule_10TestModulesSb_y")
+public func _invoke_swift_closure_TestModule_10TestModulesSb_y(_ boxPtr: UnsafeMutableRawPointer, _ param0: Int32) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending Bool) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(Bool.bridgeJSLiftParameter(param0))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_TestModule_10TestModulesSd_y")
+fileprivate func invoke_js_callback_TestModule_10TestModulesSd_y_extern(_ callback: Int32, _ param0: Float64) -> Void
+#else
+fileprivate func invoke_js_callback_TestModule_10TestModulesSd_y_extern(_ callback: Int32, _ param0: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_TestModule_10TestModulesSd_y(_ callback: Int32, _ param0: Float64) -> Void {
+    return invoke_js_callback_TestModule_10TestModulesSd_y_extern(callback, param0)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_TestModule_10TestModulesSd_y")
+fileprivate func make_swift_closure_TestModule_10TestModulesSd_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_TestModule_10TestModulesSd_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_TestModule_10TestModulesSd_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_TestModule_10TestModulesSd_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_10TestModulesSd_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending Double) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let param0Value = param0.bridgeJSLowerParameter()
+            invoke_js_callback_TestModule_10TestModulesSd_y(callbackValue, param0Value)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending Double) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending Double) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_TestModule_10TestModulesSd_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_TestModule_10TestModulesSd_y")
+@_cdecl("invoke_swift_closure_TestModule_10TestModulesSd_y")
+public func _invoke_swift_closure_TestModule_10TestModulesSd_y(_ boxPtr: UnsafeMutableRawPointer, _ param0: Float64) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending Double) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(Double.bridgeJSLiftParameter(param0))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_TestModule_10TestModulesSi_y")
+fileprivate func invoke_js_callback_TestModule_10TestModulesSi_y_extern(_ callback: Int32, _ param0: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_TestModule_10TestModulesSi_y_extern(_ callback: Int32, _ param0: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_TestModule_10TestModulesSi_y(_ callback: Int32, _ param0: Int32) -> Void {
+    return invoke_js_callback_TestModule_10TestModulesSi_y_extern(callback, param0)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_TestModule_10TestModulesSi_y")
+fileprivate func make_swift_closure_TestModule_10TestModulesSi_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_TestModule_10TestModulesSi_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_TestModule_10TestModulesSi_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_TestModule_10TestModulesSi_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_10TestModulesSi_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending Int) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let param0Value = param0.bridgeJSLowerParameter()
+            invoke_js_callback_TestModule_10TestModulesSi_y(callbackValue, param0Value)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending Int) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending Int) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_TestModule_10TestModulesSi_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_TestModule_10TestModulesSi_y")
+@_cdecl("invoke_swift_closure_TestModule_10TestModulesSi_y")
+public func _invoke_swift_closure_TestModule_10TestModulesSi_y(_ boxPtr: UnsafeMutableRawPointer, _ param0: Int32) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending Int) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(Int.bridgeJSLiftParameter(param0))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_TestModule_10TestModuley_y")
+fileprivate func invoke_js_callback_TestModule_10TestModuley_y_extern(_ callback: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_TestModule_10TestModuley_y_extern(_ callback: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_TestModule_10TestModuley_y(_ callback: Int32) -> Void {
+    return invoke_js_callback_TestModule_10TestModuley_y_extern(callback)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_TestModule_10TestModuley_y")
+fileprivate func make_swift_closure_TestModule_10TestModuley_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_TestModule_10TestModuley_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_TestModule_10TestModuley_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_TestModule_10TestModuley_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_10TestModuley_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> () -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            invoke_js_callback_TestModule_10TestModuley_y(callbackValue)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == () -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping () -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_TestModule_10TestModuley_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_TestModule_10TestModuley_y")
+@_cdecl("invoke_swift_closure_TestModule_10TestModuley_y")
+public func _invoke_swift_closure_TestModule_10TestModuley_y(_ boxPtr: UnsafeMutableRawPointer) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<() -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure()
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_asyncReturnVoid")
+fileprivate func bjs_asyncReturnVoid_extern(_ resolveRef: Int32, _ rejectRef: Int32) -> Void
+#else
+fileprivate func bjs_asyncReturnVoid_extern(_ resolveRef: Int32, _ rejectRef: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_asyncReturnVoid(_ resolveRef: Int32, _ rejectRef: Int32) -> Void {
+    return bjs_asyncReturnVoid_extern(resolveRef, rejectRef)
+}
+
+func _$asyncReturnVoid() async throws(JSException) -> Void {
+    try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<() -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        bjs_asyncReturnVoid(resolveRef, rejectRef)
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_asyncRoundTripInt")
+fileprivate func bjs_asyncRoundTripInt_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void
+#else
+fileprivate func bjs_asyncRoundTripInt_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_asyncRoundTripInt(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    return bjs_asyncRoundTripInt_extern(resolveRef, rejectRef, v)
+}
+
+func _$asyncRoundTripInt(_ v: Int) async throws(JSException) -> Int {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending Int) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        let vValue = v.bridgeJSLowerParameter()
+        bjs_asyncRoundTripInt(resolveRef, rejectRef, vValue)
+    }
+    return resolved
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_asyncRoundTripString")
+fileprivate func bjs_asyncRoundTripString_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ vBytes: Int32, _ vLength: Int32) -> Void
+#else
+fileprivate func bjs_asyncRoundTripString_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ vBytes: Int32, _ vLength: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_asyncRoundTripString(_ resolveRef: Int32, _ rejectRef: Int32, _ vBytes: Int32, _ vLength: Int32) -> Void {
+    return bjs_asyncRoundTripString_extern(resolveRef, rejectRef, vBytes, vLength)
+}
+
+func _$asyncRoundTripString(_ v: String) async throws(JSException) -> String {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending String) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        v.bridgeJSWithLoweredParameter { (vBytes, vLength) in
+            bjs_asyncRoundTripString(resolveRef, rejectRef, vBytes, vLength)
+        }
+    }
+    return resolved
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_asyncRoundTripBool")
+fileprivate func bjs_asyncRoundTripBool_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void
+#else
+fileprivate func bjs_asyncRoundTripBool_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_asyncRoundTripBool(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    return bjs_asyncRoundTripBool_extern(resolveRef, rejectRef, v)
+}
+
+func _$asyncRoundTripBool(_ v: Bool) async throws(JSException) -> Bool {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending Bool) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        let vValue = v.bridgeJSLowerParameter()
+        bjs_asyncRoundTripBool(resolveRef, rejectRef, vValue)
+    }
+    return resolved
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_asyncRoundTripDouble")
+fileprivate func bjs_asyncRoundTripDouble_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Float64) -> Void
+#else
+fileprivate func bjs_asyncRoundTripDouble_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_asyncRoundTripDouble(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Float64) -> Void {
+    return bjs_asyncRoundTripDouble_extern(resolveRef, rejectRef, v)
+}
+
+func _$asyncRoundTripDouble(_ v: Double) async throws(JSException) -> Double {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending Double) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        let vValue = v.bridgeJSLowerParameter()
+        bjs_asyncRoundTripDouble(resolveRef, rejectRef, vValue)
+    }
+    return resolved
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "TestModule", name: "bjs_asyncRoundTripJSObject")
+fileprivate func bjs_asyncRoundTripJSObject_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void
+#else
+fileprivate func bjs_asyncRoundTripJSObject_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_asyncRoundTripJSObject(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    return bjs_asyncRoundTripJSObject_extern(resolveRef, rejectRef, v)
+}
+
+func _$asyncRoundTripJSObject(_ v: JSObject) async throws(JSException) -> JSObject {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending JSObject) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        let vValue = v.bridgeJSLowerParameter()
+        bjs_asyncRoundTripJSObject(resolveRef, rejectRef, vValue)
+    }
+    return resolved
+}
\ No newline at end of file
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/CrossFileSkipsEmptySkeletons.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/CrossFileSkipsEmptySkeletons.json
index 4d7495a7c..a0c2c80c6 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/CrossFileSkipsEmptySkeletons.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/CrossFileSkipsEmptySkeletons.json
@@ -4,6 +4,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "fetchNumber",
             "parameters" : [
 
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DictionaryTypes.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DictionaryTypes.json
index c740dc46f..ea707098d 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DictionaryTypes.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/DictionaryTypes.json
@@ -235,6 +235,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "importMirrorDictionary",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/EnumRawType.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/EnumRawType.json
index ba36405ba..fc4a7ae52 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/EnumRawType.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/EnumRawType.json
@@ -1526,6 +1526,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "takesFeatureFlag",
             "parameters" : [
               {
@@ -1545,6 +1550,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "returnsFeatureFlag",
             "parameters" : [
 
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/FixedWidthIntegers.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/FixedWidthIntegers.json
index bef9cbc88..15a20f72e 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/FixedWidthIntegers.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/FixedWidthIntegers.json
@@ -269,6 +269,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripInt8",
             "parameters" : [
               {
@@ -293,6 +298,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripUInt8",
             "parameters" : [
               {
@@ -317,6 +327,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripInt16",
             "parameters" : [
               {
@@ -341,6 +356,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripUInt16",
             "parameters" : [
               {
@@ -365,6 +385,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripInt32",
             "parameters" : [
               {
@@ -389,6 +414,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripUInt32",
             "parameters" : [
               {
@@ -413,6 +443,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripInt64",
             "parameters" : [
               {
@@ -437,6 +472,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundTripUInt64",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalGetter.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalGetter.json
index 55ac7dd70..f750fc6a5 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalGetter.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalGetter.json
@@ -22,6 +22,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "log",
                 "parameters" : [
                   {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalThisImports.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalThisImports.json
index 5e002e34f..809a9ad99 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalThisImports.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/GlobalThisImports.json
@@ -4,6 +4,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "from" : "global",
             "jsName" : "parseInt",
             "name" : "parseInt",
@@ -42,6 +47,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "log",
                 "parameters" : [
                   {
@@ -87,6 +97,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "close",
                 "parameters" : [
 
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ImportArray.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ImportArray.json
index 7f79a8146..3f9cb8e32 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ImportArray.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ImportArray.json
@@ -4,6 +4,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "roundtrip",
             "parameters" : [
               {
@@ -36,6 +41,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "logStrings",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/InvalidPropertyNames.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/InvalidPropertyNames.json
index 935f7a7f2..1ad99f397 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/InvalidPropertyNames.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/InvalidPropertyNames.json
@@ -4,6 +4,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "createWeirdObject",
             "parameters" : [
 
@@ -15,6 +20,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "createWeirdClass",
             "parameters" : [
 
@@ -100,6 +110,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "as",
                 "parameters" : [
 
@@ -111,6 +126,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "try",
                 "parameters" : [
 
@@ -218,6 +238,11 @@
             "jsName" : "$Weird",
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "jsName" : "method-with-dashes",
                 "name" : "method_with_dashes",
                 "parameters" : [
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClass.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClass.json
index 689e86150..ef8eba9ba 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClass.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClass.json
@@ -4,6 +4,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "returnAnimatable",
             "parameters" : [
 
@@ -49,6 +54,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "greet",
                 "parameters" : [
 
@@ -60,6 +70,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "changeName",
                 "parameters" : [
                   {
@@ -100,6 +115,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "animate",
                 "parameters" : [
                   {
@@ -126,6 +146,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "getAnimations",
                 "parameters" : [
                   {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClassStaticFunctions.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClassStaticFunctions.json
index a8b64558f..18f7cfaac 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClassStaticFunctions.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSClassStaticFunctions.json
@@ -12,6 +12,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "value",
                 "parameters" : [
 
@@ -29,6 +34,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "create",
                 "parameters" : [
                   {
@@ -47,6 +57,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "value",
                 "parameters" : [
 
@@ -58,6 +73,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "makeDefault",
                 "parameters" : [
 
@@ -69,6 +89,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "jsName" : "with-dashes",
                 "name" : "dashed",
                 "parameters" : [
@@ -107,6 +132,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "create",
                 "parameters" : [
                   {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSValue.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSValue.json
index 5bd83be27..fb8601ae7 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSValue.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/JSValue.json
@@ -321,6 +321,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsEchoJSValue",
             "parameters" : [
               {
@@ -339,6 +344,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsEchoJSValueArray",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Optionals.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Optionals.json
index 67d97821c..3e6d6c60c 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Optionals.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/Optionals.json
@@ -1152,6 +1152,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripStringOrNull",
                 "parameters" : [
                   {
@@ -1180,6 +1185,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripStringOrUndefined",
                 "parameters" : [
                   {
@@ -1208,6 +1218,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripDoubleOrNull",
                 "parameters" : [
                   {
@@ -1236,6 +1251,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripDoubleOrUndefined",
                 "parameters" : [
                   {
@@ -1264,6 +1284,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripBoolOrNull",
                 "parameters" : [
                   {
@@ -1292,6 +1317,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripBoolOrUndefined",
                 "parameters" : [
                   {
@@ -1320,6 +1350,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripIntOrNull",
                 "parameters" : [
                   {
@@ -1354,6 +1389,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "roundTripIntOrUndefined",
                 "parameters" : [
                   {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveParameters.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveParameters.json
index f75bf7610..cf76f3878 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveParameters.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveParameters.json
@@ -88,6 +88,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "check",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveReturn.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveReturn.json
index cded9a973..b0398c161 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveReturn.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/PrimitiveReturn.json
@@ -112,6 +112,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "checkNumber",
             "parameters" : [
 
@@ -123,6 +128,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "checkBoolean",
             "parameters" : [
 
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.json
index 4ba7ba9a5..36d6941d3 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/ProtocolInClosure.json
@@ -84,7 +84,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -130,7 +131,8 @@
                 "swiftProtocol" : {
                   "_0" : "Renderable"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -166,7 +168,8 @@
                     "swiftProtocol" : {
                       "_0" : "Renderable"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -191,7 +194,8 @@
                 "swiftProtocol" : {
                   "_0" : "Renderable"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -232,7 +236,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringParameter.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringParameter.json
index b0aa8c35b..75462af81 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringParameter.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringParameter.json
@@ -71,6 +71,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "checkString",
             "parameters" : [
               {
@@ -89,6 +94,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "checkStringWithLength",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringReturn.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringReturn.json
index 3f9271592..1088a5cab 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringReturn.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/StringReturn.json
@@ -38,6 +38,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "checkString",
             "parameters" : [
 
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClass.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClass.json
index 6ab78c82c..ceda64904 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClass.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClass.json
@@ -213,6 +213,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripGreeter",
             "parameters" : [
               {
@@ -231,6 +236,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripOptionalGreeter",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosure.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosure.json
index f610d4bde..41662e48b 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosure.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosure.json
@@ -61,7 +61,8 @@
                       "string" : {
 
                       }
-                    }
+                    },
+                    "sendingParameters" : false
                   },
                   "useJSTypedClosure" : false
                 }
@@ -313,7 +314,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -338,7 +340,8 @@
                 "string" : {
 
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -380,7 +383,8 @@
                         "width" : "word"
                       }
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -411,7 +415,8 @@
                     "width" : "word"
                   }
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -447,7 +452,8 @@
                     "bool" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -472,7 +478,8 @@
                 "bool" : {
 
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -508,7 +515,8 @@
                     "float" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -533,7 +541,8 @@
                 "float" : {
 
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -569,7 +578,8 @@
                     "double" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -594,7 +604,8 @@
                 "double" : {
 
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -640,7 +651,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -675,7 +687,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -727,7 +740,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -768,7 +782,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -814,7 +829,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -849,7 +865,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -895,7 +912,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -930,7 +948,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -976,7 +995,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1011,7 +1031,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1047,7 +1068,8 @@
                     "swiftHeapObject" : {
                       "_0" : "Person"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1072,7 +1094,8 @@
                 "swiftHeapObject" : {
                   "_0" : "Person"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1118,7 +1141,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1153,7 +1177,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1189,7 +1214,8 @@
                     "caseEnum" : {
                       "_0" : "Direction"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1214,7 +1240,8 @@
                 "caseEnum" : {
                   "_0" : "Direction"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1252,7 +1279,8 @@
                       "_0" : "Theme",
                       "_1" : "String"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1279,7 +1307,8 @@
                   "_0" : "Theme",
                   "_1" : "String"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1317,7 +1346,8 @@
                       "_0" : "HttpStatus",
                       "_1" : "Int"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1344,7 +1374,8 @@
                   "_0" : "HttpStatus",
                   "_1" : "Int"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1380,7 +1411,8 @@
                     "associatedValueEnum" : {
                       "_0" : "APIResult"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1405,7 +1437,8 @@
                 "associatedValueEnum" : {
                   "_0" : "APIResult"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1451,7 +1484,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1486,7 +1520,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1534,7 +1569,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1571,7 +1607,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1619,7 +1656,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1656,7 +1694,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1702,7 +1741,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1737,7 +1777,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -1783,7 +1824,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -1818,7 +1860,8 @@
                   },
                   "_1" : "null"
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosureImports.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosureImports.json
index 4359b50ec..a78b1bf5d 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosureImports.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftClosureImports.json
@@ -4,6 +4,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "applyInt",
             "parameters" : [
               {
@@ -43,7 +48,8 @@
                             "width" : "word"
                           }
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -60,6 +66,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "makeAdder",
             "parameters" : [
               {
@@ -98,7 +109,8 @@
                         "width" : "word"
                       }
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftStructImports.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftStructImports.json
index c1329cd79..ccd3043ac 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftStructImports.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/SwiftStructImports.json
@@ -56,6 +56,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "translate",
             "parameters" : [
               {
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/VoidParameterVoidReturn.json b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/VoidParameterVoidReturn.json
index 14da32841..7f19c18bf 100644
--- a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/VoidParameterVoidReturn.json
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSCodegenTests/VoidParameterVoidReturn.json
@@ -38,6 +38,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "check",
             "parameters" : [
 
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/AsyncImport.d.ts b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/AsyncImport.d.ts
new file mode 100644
index 000000000..e612ae1e1
--- /dev/null
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/AsyncImport.d.ts
@@ -0,0 +1,23 @@
+// NOTICE: This is auto-generated code by BridgeJS from JavaScriptKit,
+// DO NOT EDIT.
+//
+// To update this file, just rebuild your project or run
+// `swift package bridge-js`.
+
+export type Exports = {
+}
+export type Imports = {
+    asyncReturnVoid(): Promise<void>;
+    asyncRoundTripInt(v: number): Promise<number>;
+    asyncRoundTripString(v: string): Promise<string>;
+    asyncRoundTripBool(v: boolean): Promise<boolean>;
+    asyncRoundTripDouble(v: number): Promise<number>;
+    asyncRoundTripJSObject(v: any): Promise<any>;
+}
+export function createInstantiator(options: {
+    imports: Imports;
+}, swift: any): Promise<{
+    addImports: (importObject: WebAssembly.Imports) => void;
+    setInstance: (instance: WebAssembly.Instance) => void;
+    createExports: (instance: WebAssembly.Instance) => Exports;
+}>;
\ No newline at end of file
diff --git a/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/AsyncImport.js b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/AsyncImport.js
new file mode 100644
index 000000000..89ab29827
--- /dev/null
+++ b/Plugins/BridgeJS/Tests/BridgeJSToolTests/__Snapshots__/BridgeJSLinkTests/AsyncImport.js
@@ -0,0 +1,507 @@
+// NOTICE: This is auto-generated code by BridgeJS from JavaScriptKit,
+// DO NOT EDIT.
+//
+// To update this file, just rebuild your project or run
+// `swift package bridge-js`.
+
+export async function createInstantiator(options, swift) {
+    let instance;
+    let memory;
+    let setException;
+    let decodeString;
+    const textDecoder = new TextDecoder("utf-8");
+    const textEncoder = new TextEncoder("utf-8");
+    let tmpRetString;
+    let tmpRetBytes;
+    let tmpRetException;
+    let tmpRetOptionalBool;
+    let tmpRetOptionalInt;
+    let tmpRetOptionalFloat;
+    let tmpRetOptionalDouble;
+    let tmpRetOptionalHeapObject;
+    let strStack = [];
+    let i32Stack = [];
+    let i64Stack = [];
+    let f32Stack = [];
+    let f64Stack = [];
+    let ptrStack = [];
+    const enumHelpers = {};
+    const structHelpers = {};
+
+    let _exports = null;
+    let bjs = null;
+    function __bjs_jsValueLower(value) {
+        let kind;
+        let payload1;
+        let payload2;
+        if (value === null) {
+            kind = 4;
+            payload1 = 0;
+            payload2 = 0;
+        } else {
+            switch (typeof value) {
+                case "boolean":
+                    kind = 0;
+                    payload1 = value ? 1 : 0;
+                    payload2 = 0;
+                    break;
+                case "number":
+                    kind = 2;
+                    payload1 = 0;
+                    payload2 = value;
+                    break;
+                case "string":
+                    kind = 1;
+                    payload1 = swift.memory.retain(value);
+                    payload2 = 0;
+                    break;
+                case "undefined":
+                    kind = 5;
+                    payload1 = 0;
+                    payload2 = 0;
+                    break;
+                case "object":
+                    kind = 3;
+                    payload1 = swift.memory.retain(value);
+                    payload2 = 0;
+                    break;
+                case "function":
+                    kind = 3;
+                    payload1 = swift.memory.retain(value);
+                    payload2 = 0;
+                    break;
+                case "symbol":
+                    kind = 7;
+                    payload1 = swift.memory.retain(value);
+                    payload2 = 0;
+                    break;
+                case "bigint":
+                    kind = 8;
+                    payload1 = swift.memory.retain(value);
+                    payload2 = 0;
+                    break;
+                default:
+                    throw new TypeError("Unsupported JSValue type");
+            }
+        }
+        return [kind, payload1, payload2];
+    }
+    function __bjs_jsValueLift(kind, payload1, payload2) {
+        let jsValue;
+        switch (kind) {
+            case 0:
+                jsValue = payload1 !== 0;
+                break;
+            case 1:
+                jsValue = swift.memory.getObject(payload1);
+                break;
+            case 2:
+                jsValue = payload2;
+                break;
+            case 3:
+                jsValue = swift.memory.getObject(payload1);
+                break;
+            case 4:
+                jsValue = null;
+                break;
+            case 5:
+                jsValue = undefined;
+                break;
+            case 7:
+                jsValue = swift.memory.getObject(payload1);
+                break;
+            case 8:
+                jsValue = swift.memory.getObject(payload1);
+                break;
+            default:
+                throw new TypeError("Unsupported JSValue kind " + kind);
+        }
+        return jsValue;
+    }
+
+    const swiftClosureRegistry = (typeof FinalizationRegistry === "undefined") ? { register: () => {}, unregister: () => {} } : new FinalizationRegistry((state) => {
+        if (state.unregistered) { return; }
+        instance?.exports?.bjs_release_swift_closure(state.pointer);
+    });
+    const makeClosure = (pointer, file, line, func) => {
+        const state = { pointer, file, line, unregistered: false };
+        const real = (...args) => {
+            if (state.unregistered) {
+                const bytes = new Uint8Array(memory.buffer, state.file);
+                let length = 0;
+                while (bytes[length] !== 0) { length += 1; }
+                const fileID = decodeString(state.file, length);
+                throw new Error(`Attempted to call a released JSTypedClosure created at ${fileID}:${state.line}`);
+            }
+            return func(...args);
+        };
+        real.__unregister = () => {
+            if (state.unregistered) { return; }
+            state.unregistered = true;
+            swiftClosureRegistry.unregister(state);
+        };
+        swiftClosureRegistry.register(real, state, state);
+        return swift.memory.retain(real);
+    };
+
+
+    return {
+        /**
+         * @param {WebAssembly.Imports} importObject
+         */
+        addImports: (importObject, importsContext) => {
+            bjs = {};
+            importObject["bjs"] = bjs;
+            const imports = options.getImports(importsContext);
+            bjs["swift_js_return_string"] = function(ptr, len) {
+                tmpRetString = decodeString(ptr, len);
+            }
+            bjs["swift_js_init_memory"] = function(sourceId, bytesPtr) {
+                const source = swift.memory.getObject(sourceId);
+                swift.memory.release(sourceId);
+                const bytes = new Uint8Array(memory.buffer, bytesPtr);
+                bytes.set(source);
+            }
+            bjs["swift_js_make_js_string"] = function(ptr, len) {
+                return swift.memory.retain(decodeString(ptr, len));
+            }
+            bjs["swift_js_init_memory_with_result"] = function(ptr, len) {
+                const target = new Uint8Array(memory.buffer, ptr, len);
+                target.set(tmpRetBytes);
+                tmpRetBytes = undefined;
+            }
+            bjs["swift_js_throw"] = function(id) {
+                tmpRetException = swift.memory.retainByRef(id);
+            }
+            bjs["swift_js_retain"] = function(id) {
+                return swift.memory.retainByRef(id);
+            }
+            bjs["swift_js_release"] = function(id) {
+                swift.memory.release(id);
+            }
+            bjs["swift_js_push_i32"] = function(v) {
+                i32Stack.push(v | 0);
+            }
+            bjs["swift_js_push_f32"] = function(v) {
+                f32Stack.push(Math.fround(v));
+            }
+            bjs["swift_js_push_f64"] = function(v) {
+                f64Stack.push(v);
+            }
+            bjs["swift_js_push_string"] = function(ptr, len) {
+                const value = decodeString(ptr, len);
+                strStack.push(value);
+            }
+            bjs["swift_js_pop_i32"] = function() {
+                return i32Stack.pop();
+            }
+            bjs["swift_js_pop_f32"] = function() {
+                return f32Stack.pop();
+            }
+            bjs["swift_js_pop_f64"] = function() {
+                return f64Stack.pop();
+            }
+            bjs["swift_js_push_pointer"] = function(pointer) {
+                ptrStack.push(pointer);
+            }
+            bjs["swift_js_pop_pointer"] = function() {
+                return ptrStack.pop();
+            }
+            bjs["swift_js_push_i64"] = function(v) {
+                i64Stack.push(v);
+            }
+            bjs["swift_js_pop_i64"] = function() {
+                return i64Stack.pop();
+            }
+            bjs["swift_js_return_optional_bool"] = function(isSome, value) {
+                if (isSome === 0) {
+                    tmpRetOptionalBool = null;
+                } else {
+                    tmpRetOptionalBool = value !== 0;
+                }
+            }
+            bjs["swift_js_return_optional_int"] = function(isSome, value) {
+                if (isSome === 0) {
+                    tmpRetOptionalInt = null;
+                } else {
+                    tmpRetOptionalInt = value | 0;
+                }
+            }
+            bjs["swift_js_return_optional_float"] = function(isSome, value) {
+                if (isSome === 0) {
+                    tmpRetOptionalFloat = null;
+                } else {
+                    tmpRetOptionalFloat = Math.fround(value);
+                }
+            }
+            bjs["swift_js_return_optional_double"] = function(isSome, value) {
+                if (isSome === 0) {
+                    tmpRetOptionalDouble = null;
+                } else {
+                    tmpRetOptionalDouble = value;
+                }
+            }
+            bjs["swift_js_return_optional_string"] = function(isSome, ptr, len) {
+                if (isSome === 0) {
+                    tmpRetString = null;
+                } else {
+                    tmpRetString = decodeString(ptr, len);
+                }
+            }
+            bjs["swift_js_return_optional_object"] = function(isSome, objectId) {
+                if (isSome === 0) {
+                    tmpRetString = null;
+                } else {
+                    tmpRetString = swift.memory.getObject(objectId);
+                }
+            }
+            bjs["swift_js_return_optional_heap_object"] = function(isSome, pointer) {
+                if (isSome === 0) {
+                    tmpRetOptionalHeapObject = null;
+                } else {
+                    tmpRetOptionalHeapObject = pointer;
+                }
+            }
+            bjs["swift_js_get_optional_int_presence"] = function() {
+                return tmpRetOptionalInt != null ? 1 : 0;
+            }
+            bjs["swift_js_get_optional_int_value"] = function() {
+                const value = tmpRetOptionalInt;
+                tmpRetOptionalInt = undefined;
+                return value;
+            }
+            bjs["swift_js_get_optional_string"] = function() {
+                const str = tmpRetString;
+                tmpRetString = undefined;
+                if (str == null) {
+                    return -1;
+                } else {
+                    const bytes = textEncoder.encode(str);
+                    tmpRetBytes = bytes;
+                    return bytes.length;
+                }
+            }
+            bjs["swift_js_get_optional_float_presence"] = function() {
+                return tmpRetOptionalFloat != null ? 1 : 0;
+            }
+            bjs["swift_js_get_optional_float_value"] = function() {
+                const value = tmpRetOptionalFloat;
+                tmpRetOptionalFloat = undefined;
+                return value;
+            }
+            bjs["swift_js_get_optional_double_presence"] = function() {
+                return tmpRetOptionalDouble != null ? 1 : 0;
+            }
+            bjs["swift_js_get_optional_double_value"] = function() {
+                const value = tmpRetOptionalDouble;
+                tmpRetOptionalDouble = undefined;
+                return value;
+            }
+            bjs["swift_js_get_optional_heap_object_pointer"] = function() {
+                const pointer = tmpRetOptionalHeapObject;
+                tmpRetOptionalHeapObject = undefined;
+                return pointer || 0;
+            }
+            bjs["swift_js_closure_unregister"] = function(funcRef) {}
+            bjs["swift_js_closure_unregister"] = function(funcRef) {
+                const func = swift.memory.getObject(funcRef);
+                func.__unregister();
+            }
+            bjs["invoke_js_callback_TestModule_10TestModules7JSValueV_y"] = function(callbackId, param0Kind, param0Payload1, param0Payload2) {
+                try {
+                    const callback = swift.memory.getObject(callbackId);
+                    const jsValue = __bjs_jsValueLift(param0Kind, param0Payload1, param0Payload2);
+                    callback(jsValue);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            bjs["make_swift_closure_TestModule_10TestModules7JSValueV_y"] = function(boxPtr, file, line) {
+                const lower_closure_TestModule_10TestModules7JSValueV_y = function(param0) {
+                    const [param0Kind, param0Payload1, param0Payload2] = __bjs_jsValueLower(param0);
+                    instance.exports.invoke_swift_closure_TestModule_10TestModules7JSValueV_y(boxPtr, param0Kind, param0Payload1, param0Payload2);
+                    if (tmpRetException) {
+                        const error = swift.memory.getObject(tmpRetException);
+                        swift.memory.release(tmpRetException);
+                        tmpRetException = undefined;
+                        throw error;
+                    }
+                };
+                return makeClosure(boxPtr, file, line, lower_closure_TestModule_10TestModules7JSValueV_y);
+            }
+            bjs["invoke_js_callback_TestModule_10TestModules8JSObjectC_y"] = function(callbackId, param0) {
+                try {
+                    const callback = swift.memory.getObject(callbackId);
+                    callback(swift.memory.getObject(param0));
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            bjs["make_swift_closure_TestModule_10TestModules8JSObjectC_y"] = function(boxPtr, file, line) {
+                const lower_closure_TestModule_10TestModules8JSObjectC_y = function(param0) {
+                    instance.exports.invoke_swift_closure_TestModule_10TestModules8JSObjectC_y(boxPtr, swift.memory.retain(param0));
+                    if (tmpRetException) {
+                        const error = swift.memory.getObject(tmpRetException);
+                        swift.memory.release(tmpRetException);
+                        tmpRetException = undefined;
+                        throw error;
+                    }
+                };
+                return makeClosure(boxPtr, file, line, lower_closure_TestModule_10TestModules8JSObjectC_y);
+            }
+            bjs["invoke_js_callback_TestModule_10TestModulesSS_y"] = function(callbackId, param0Bytes, param0Count) {
+                try {
+                    const callback = swift.memory.getObject(callbackId);
+                    const string = decodeString(param0Bytes, param0Count);
+                    callback(string);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            bjs["make_swift_closure_TestModule_10TestModulesSS_y"] = function(boxPtr, file, line) {
+                const lower_closure_TestModule_10TestModulesSS_y = function(param0) {
+                    const param0Bytes = textEncoder.encode(param0);
+                    const param0Id = swift.memory.retain(param0Bytes);
+                    instance.exports.invoke_swift_closure_TestModule_10TestModulesSS_y(boxPtr, param0Id, param0Bytes.length);
+                    if (tmpRetException) {
+                        const error = swift.memory.getObject(tmpRetException);
+                        swift.memory.release(tmpRetException);
+                        tmpRetException = undefined;
+                        throw error;
+                    }
+                };
+                return makeClosure(boxPtr, file, line, lower_closure_TestModule_10TestModulesSS_y);
+            }
+            bjs["invoke_js_callback_TestModule_10TestModulesSb_y"] = function(callbackId, param0) {
+                try {
+                    const callback = swift.memory.getObject(callbackId);
+                    callback(param0 !== 0);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            bjs["make_swift_closure_TestModule_10TestModulesSb_y"] = function(boxPtr, file, line) {
+                const lower_closure_TestModule_10TestModulesSb_y = function(param0) {
+                    instance.exports.invoke_swift_closure_TestModule_10TestModulesSb_y(boxPtr, param0);
+                    if (tmpRetException) {
+                        const error = swift.memory.getObject(tmpRetException);
+                        swift.memory.release(tmpRetException);
+                        tmpRetException = undefined;
+                        throw error;
+                    }
+                };
+                return makeClosure(boxPtr, file, line, lower_closure_TestModule_10TestModulesSb_y);
+            }
+            bjs["invoke_js_callback_TestModule_10TestModulesSd_y"] = function(callbackId, param0) {
+                try {
+                    const callback = swift.memory.getObject(callbackId);
+                    callback(param0);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            bjs["make_swift_closure_TestModule_10TestModulesSd_y"] = function(boxPtr, file, line) {
+                const lower_closure_TestModule_10TestModulesSd_y = function(param0) {
+                    instance.exports.invoke_swift_closure_TestModule_10TestModulesSd_y(boxPtr, param0);
+                    if (tmpRetException) {
+                        const error = swift.memory.getObject(tmpRetException);
+                        swift.memory.release(tmpRetException);
+                        tmpRetException = undefined;
+                        throw error;
+                    }
+                };
+                return makeClosure(boxPtr, file, line, lower_closure_TestModule_10TestModulesSd_y);
+            }
+            bjs["invoke_js_callback_TestModule_10TestModulesSi_y"] = function(callbackId, param0) {
+                try {
+                    const callback = swift.memory.getObject(callbackId);
+                    callback(param0);
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            bjs["make_swift_closure_TestModule_10TestModulesSi_y"] = function(boxPtr, file, line) {
+                const lower_closure_TestModule_10TestModulesSi_y = function(param0) {
+                    instance.exports.invoke_swift_closure_TestModule_10TestModulesSi_y(boxPtr, param0);
+                    if (tmpRetException) {
+                        const error = swift.memory.getObject(tmpRetException);
+                        swift.memory.release(tmpRetException);
+                        tmpRetException = undefined;
+                        throw error;
+                    }
+                };
+                return makeClosure(boxPtr, file, line, lower_closure_TestModule_10TestModulesSi_y);
+            }
+            bjs["invoke_js_callback_TestModule_10TestModuley_y"] = function(callbackId) {
+                try {
+                    const callback = swift.memory.getObject(callbackId);
+                    callback();
+                } catch (error) {
+                    setException(error);
+                }
+            }
+            bjs["make_swift_closure_TestModule_10TestModuley_y"] = function(boxPtr, file, line) {
+                const lower_closure_TestModule_10TestModuley_y = function() {
+                    instance.exports.invoke_swift_closure_TestModule_10TestModuley_y(boxPtr);
+                    if (tmpRetException) {
+                        const error = swift.memory.getObject(tmpRetException);
+                        swift.memory.release(tmpRetException);
+                        tmpRetException = undefined;
+                        throw error;
+                    }
+                };
+                return makeClosure(boxPtr, file, line, lower_closure_TestModule_10TestModuley_y);
+            }
+            const TestModule = importObject["TestModule"] = importObject["TestModule"] || {};
+            TestModule["bjs_asyncReturnVoid"] = function bjs_asyncReturnVoid(resolveRef, rejectRef) {
+                const resolve = swift.memory.getObject(resolveRef);
+                const reject = swift.memory.getObject(rejectRef);
+                imports.asyncReturnVoid().then(resolve, reject);
+            }
+            TestModule["bjs_asyncRoundTripInt"] = function bjs_asyncRoundTripInt(resolveRef, rejectRef, v) {
+                const resolve = swift.memory.getObject(resolveRef);
+                const reject = swift.memory.getObject(rejectRef);
+                imports.asyncRoundTripInt(v).then(resolve, reject);
+            }
+            TestModule["bjs_asyncRoundTripString"] = function bjs_asyncRoundTripString(resolveRef, rejectRef, vBytes, vCount) {
+                const resolve = swift.memory.getObject(resolveRef);
+                const reject = swift.memory.getObject(rejectRef);
+                const string = decodeString(vBytes, vCount);
+                imports.asyncRoundTripString(string).then(resolve, reject);
+            }
+            TestModule["bjs_asyncRoundTripBool"] = function bjs_asyncRoundTripBool(resolveRef, rejectRef, v) {
+                const resolve = swift.memory.getObject(resolveRef);
+                const reject = swift.memory.getObject(rejectRef);
+                imports.asyncRoundTripBool(v !== 0).then(resolve, reject);
+            }
+            TestModule["bjs_asyncRoundTripDouble"] = function bjs_asyncRoundTripDouble(resolveRef, rejectRef, v) {
+                const resolve = swift.memory.getObject(resolveRef);
+                const reject = swift.memory.getObject(rejectRef);
+                imports.asyncRoundTripDouble(v).then(resolve, reject);
+            }
+            TestModule["bjs_asyncRoundTripJSObject"] = function bjs_asyncRoundTripJSObject(resolveRef, rejectRef, v) {
+                const resolve = swift.memory.getObject(resolveRef);
+                const reject = swift.memory.getObject(rejectRef);
+                imports.asyncRoundTripJSObject(swift.memory.getObject(v)).then(resolve, reject);
+            }
+        },
+        setInstance: (i) => {
+            instance = i;
+            memory = instance.exports.memory;
+
+            decodeString = (ptr, len) => { const bytes = new Uint8Array(memory.buffer, ptr >>> 0, len >>> 0); return textDecoder.decode(bytes); }
+
+            setException = (error) => {
+                instance.exports._swift_js_exception.value = swift.memory.retain(error)
+            }
+        },
+        /** @param {WebAssembly.Instance} instance */
+        createExports: (instance) => {
+            const js = swift.memory.heap;
+            const exports = {
+            };
+            _exports = exports;
+            return exports;
+        },
+    }
+}
\ No newline at end of file
diff --git a/Sources/JavaScriptKit/BridgeJSIntrinsics.swift b/Sources/JavaScriptKit/BridgeJSIntrinsics.swift
index 180567ed1..867d0e835 100644
--- a/Sources/JavaScriptKit/BridgeJSIntrinsics.swift
+++ b/Sources/JavaScriptKit/BridgeJSIntrinsics.swift
@@ -4,6 +4,7 @@
 /// by the BridgeJS system.
 
 import _CJavaScriptKit
+import _Concurrency
 
 #if !arch(wasm32)
 @usableFromInline func _onlyAvailableOnWasm() -> Never {
@@ -2083,3 +2084,91 @@ extension _BridgedAsOptional {
         Wrapped.bridgeJSStackPushAsOptional(asOptional)
     }
 }
+
+// MARK: Async Promise Awaiting
+
+/// Protocol for type-erasing `JSTypedClosure` in `_bjs_awaitPromise`.
+///
+/// The library cannot name concrete `JSTypedClosure<(Int) -> Void>` etc. because
+/// those require per-module generated convenience inits. This protocol provides
+/// access to the underlying JS object ref and cleanup.
+@_spi(BridgeJS) public protocol _BridgeJSReleasableClosure {
+    var jsObject: JSObject { get }
+    func release()
+}
+
+@_spi(BridgeJS) extension JSTypedClosure: _BridgeJSReleasableClosure {}
+
+/// Awaits a JavaScript Promise using typed resolve/reject `JSTypedClosure` callbacks.
+///
+/// The closure factories are dependency-injected because this library cannot
+/// reference per-module generated `make_swift_closure_*` externs. The generated
+/// code passes `{ JSTypedClosure<(T) -> Void>($0) }` which uses the per-module
+/// convenience init.
+///
+/// - Parameters:
+///   - makeResolveClosure: A factory that wraps a `(T) -> Void` Swift closure
+///     into a typed `JSTypedClosure`, creating the corresponding JS function.
+///   - makeRejectClosure: A factory that wraps a `(JSValue) -> Void` Swift closure
+///     into a `JSTypedClosure`, for the rejection path.
+///   - body: A closure that receives the resolve and reject JS object refs
+///     (as `Int32`) and should pass them to the appropriate JS extern function.
+/// - Returns: The resolved value of type `T` from the Promise.
+/// - Throws: `JSException` if the Promise rejects.
+@_spi(BridgeJS) public func _bjs_awaitPromise<T, R: _BridgeJSReleasableClosure, E: _BridgeJSReleasableClosure>(
+    makeResolveClosure: (@escaping (sending T) -> Void) -> R,
+    makeRejectClosure: (@escaping (sending JSValue) -> Void) -> E,
+    _ body: (_ resolveRef: Int32, _ rejectRef: Int32) -> Void
+) async throws(JSException) -> T {
+    var resolveClosure: R?
+    var rejectClosure: E?
+    let result: Result<T, JSException> = await withCheckedContinuation { continuation in
+        let resolve = makeResolveClosure { value in
+            continuation.resume(returning: .success(value))
+        }
+        let reject = makeRejectClosure { value in
+            continuation.resume(returning: .failure(JSException(value)))
+        }
+        resolveClosure = resolve
+        rejectClosure = reject
+        body(
+            Int32(bitPattern: resolve.jsObject.id),
+            Int32(bitPattern: reject.jsObject.id)
+        )
+    }
+    resolveClosure?.release()
+    rejectClosure?.release()
+    return try result.get()
+}
+
+/// Void-returning overload of `_bjs_awaitPromise`.
+///
+/// Needed because `(Void) -> Void` is not the same as `() -> Void` in Swift (SE-0110),
+/// so the generic overload cannot handle void returns.
+@_spi(BridgeJS) public func _bjs_awaitPromise<R: _BridgeJSReleasableClosure, E: _BridgeJSReleasableClosure>(
+    makeResolveClosure: (@escaping () -> Void) -> R,
+    makeRejectClosure: (@escaping (sending JSValue) -> Void) -> E,
+    _ body: (_ resolveRef: Int32, _ rejectRef: Int32) -> Void
+) async throws(JSException) {
+    var resolveClosure: R?
+    var rejectClosure: E?
+    let error: JSException? = await withCheckedContinuation { continuation in
+        let resolve = makeResolveClosure {
+            continuation.resume(returning: nil)
+        }
+        let reject = makeRejectClosure { value in
+            continuation.resume(returning: JSException(value))
+        }
+        resolveClosure = resolve
+        rejectClosure = reject
+        body(
+            Int32(bitPattern: resolve.jsObject.id),
+            Int32(bitPattern: reject.jsObject.id)
+        )
+    }
+    resolveClosure?.release()
+    rejectClosure?.release()
+    if let error {
+        throw error
+    }
+}
diff --git a/Tests/BridgeJSRuntimeTests/AsyncImportTests.swift b/Tests/BridgeJSRuntimeTests/AsyncImportTests.swift
new file mode 100644
index 000000000..9b6cc0688
--- /dev/null
+++ b/Tests/BridgeJSRuntimeTests/AsyncImportTests.swift
@@ -0,0 +1,35 @@
+import Testing
+import JavaScriptKit
+
+@Suite struct AsyncImportTests {
+    @Test func asyncRoundTripVoid() async throws {
+        try await jsAsyncRoundTripVoid()
+    }
+
+    @Test(arguments: [0.0, 1.0, -1.0, Double.pi, Double.infinity])
+    func asyncRoundTripNumber(v: Double) async throws {
+        try #expect(await jsAsyncRoundTripNumber(v) == v)
+    }
+
+    @Test(arguments: [true, false])
+    func asyncRoundTripBool(v: Bool) async throws {
+        try #expect(await jsAsyncRoundTripBool(v) == v)
+    }
+
+    @Test(arguments: ["", "Hello, world!", "🧑‍🧑‍🧒"])
+    func asyncRoundTripString(v: String) async throws {
+        try #expect(await jsAsyncRoundTripString(v) == v)
+    }
+
+    @Test func fetchWeatherData() async throws {
+        let weather = try await BridgeJSRuntimeTests.fetchWeatherData("London")
+        #expect(try weather.temperature == 15.5)
+        #expect(try weather.description == "Cloudy")
+        #expect(try weather.humidity == 80)
+
+        let weather2 = try await BridgeJSRuntimeTests.fetchWeatherData("Tokyo")
+        #expect(try weather2.temperature == 25.0)
+        #expect(try weather2.description == "Sunny")
+        #expect(try weather2.humidity == 40)
+    }
+}
diff --git a/Tests/BridgeJSRuntimeTests/ExportAPITests.swift b/Tests/BridgeJSRuntimeTests/ExportAPITests.swift
index 171d0dd3a..3db9497fc 100644
--- a/Tests/BridgeJSRuntimeTests/ExportAPITests.swift
+++ b/Tests/BridgeJSRuntimeTests/ExportAPITests.swift
@@ -1301,6 +1301,6 @@ class ExportAPITests: XCTestCase {
     }
 
     func testAllAsync() async throws {
-        _ = try await runAsyncWorks().value()
+        try await runAsyncWorks()
     }
 }
diff --git a/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.Macros.swift b/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.Macros.swift
index ac9ad0bc6..b4e780bee 100644
--- a/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.Macros.swift
+++ b/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.Macros.swift
@@ -41,7 +41,26 @@ extension FeatureFlag: _BridgedSwiftEnumNoPayload, _BridgedSwiftRawValueEnum {}
     @JSFunction func changeName(_ name: String) throws(JSException) -> Void
 }
 
-@JSFunction func runAsyncWorks() throws(JSException) -> JSPromise
+@JSFunction func runAsyncWorks() async throws(JSException) -> Void
+
+@JSFunction func jsAsyncRoundTripVoid() async throws(JSException) -> Void
+
+@JSFunction func jsAsyncRoundTripNumber(_ v: Double) async throws(JSException) -> Double
+
+@JSFunction func jsAsyncRoundTripBool(_ v: Bool) async throws(JSException) -> Bool
+
+@JSFunction func jsAsyncRoundTripString(_ v: String) async throws(JSException) -> String
+
+@JSFunction func fetchWeatherData(_ city: String) async throws(JSException) -> WeatherData
+
+@JSClass struct WeatherData {
+    @JSGetter var temperature: Double
+    @JSSetter func setTemperature(_ value: Double) throws(JSException)
+    @JSGetter var description: String
+    @JSSetter func setDescription(_ value: String) throws(JSException)
+    @JSGetter var humidity: Double
+    @JSSetter func setHumidity(_ value: Double) throws(JSException)
+}
 
 @JSFunction(jsName: "$jsWeirdFunction") func _jsWeirdFunction() throws(JSException) -> Double
 
diff --git a/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift b/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift
index b54106be9..b7d6b55c3 100644
--- a/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift
+++ b/Tests/BridgeJSRuntimeTests/Generated/BridgeJS.swift
@@ -1674,6 +1674,312 @@ public func _invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestsSqS
     #endif
 }
 
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y")
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y_extern(_ callback: Int32, _ param0: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y_extern(_ callback: Int32, _ param0: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y(_ callback: Int32, _ param0: Int32) -> Void {
+    return invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y_extern(callback, param0)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y")
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_20BridgeJSRuntimeTestss11WeatherDataC_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending WeatherData) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let param0Value = param0.bridgeJSLowerParameter()
+            invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y(callbackValue, param0Value)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending WeatherData) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending WeatherData) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y")
+@_cdecl("invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y")
+public func _invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss11WeatherDataC_y(_ boxPtr: UnsafeMutableRawPointer, _ param0: Int32) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending WeatherData) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(WeatherData.bridgeJSLiftParameter(param0))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y")
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y_extern(_ callback: Int32, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void
+#else
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y_extern(_ callback: Int32, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y(_ callback: Int32, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void {
+    return invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y_extern(callback, param0Kind, param0Payload1, param0Payload2)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y")
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_20BridgeJSRuntimeTestss7JSValueV_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending JSValue) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let (param0Kind, param0Payload1, param0Payload2) = param0.bridgeJSLowerParameter()
+            invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y(callbackValue, param0Kind, param0Payload1, param0Payload2)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending JSValue) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending JSValue) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y")
+@_cdecl("invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y")
+public func _invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestss7JSValueV_y(_ boxPtr: UnsafeMutableRawPointer, _ param0Kind: Int32, _ param0Payload1: Int32, _ param0Payload2: Float64) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending JSValue) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(JSValue.bridgeJSLiftParameter(param0Kind, param0Payload1, param0Payload2))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y")
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y_extern(_ callback: Int32, _ param0Bytes: Int32, _ param0Length: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y_extern(_ callback: Int32, _ param0Bytes: Int32, _ param0Length: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y(_ callback: Int32, _ param0Bytes: Int32, _ param0Length: Int32) -> Void {
+    return invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y_extern(callback, param0Bytes, param0Length)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y")
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_20BridgeJSRuntimeTestssSS_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending String) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            param0.bridgeJSWithLoweredParameter { (param0Bytes, param0Length) in
+                invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y(callbackValue, param0Bytes, param0Length)
+            }
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending String) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending String) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y")
+@_cdecl("invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y")
+public func _invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSS_y(_ boxPtr: UnsafeMutableRawPointer, _ param0Bytes: Int32, _ param0Length: Int32) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending String) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(String.bridgeJSLiftParameter(param0Bytes, param0Length))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y")
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y_extern(_ callback: Int32, _ param0: Int32) -> Void
+#else
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y_extern(_ callback: Int32, _ param0: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y(_ callback: Int32, _ param0: Int32) -> Void {
+    return invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y_extern(callback, param0)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y")
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_20BridgeJSRuntimeTestssSb_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending Bool) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let param0Value = param0.bridgeJSLowerParameter()
+            invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y(callbackValue, param0Value)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending Bool) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending Bool) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y")
+@_cdecl("invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y")
+public func _invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSb_y(_ boxPtr: UnsafeMutableRawPointer, _ param0: Int32) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending Bool) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(Bool.bridgeJSLiftParameter(param0))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y")
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y_extern(_ callback: Int32, _ param0: Float64) -> Void
+#else
+fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y_extern(_ callback: Int32, _ param0: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y(_ callback: Int32, _ param0: Float64) -> Void {
+    return invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y_extern(callback, param0)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "bjs", name: "make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y")
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32
+#else
+fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y_extern(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y(_ boxPtr: UnsafeMutableRawPointer, _ file: UnsafePointer<UInt8>, _ line: UInt32) -> Int32 {
+    return make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y_extern(boxPtr, file, line)
+}
+
+private enum _BJS_Closure_20BridgeJSRuntimeTestssSd_y {
+    static func bridgeJSLift(_ callbackId: Int32) -> (sending Double) -> Void {
+        let callback = JSObject.bridgeJSLiftParameter(callbackId)
+        return { [callback] param0 in
+            #if arch(wasm32)
+            let callbackValue = callback.bridgeJSLowerParameter()
+            let param0Value = param0.bridgeJSLowerParameter()
+            invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y(callbackValue, param0Value)
+            #else
+            fatalError("Only available on WebAssembly")
+            #endif
+        }
+    }
+}
+
+extension JSTypedClosure where Signature == (sending Double) -> Void {
+    init(fileID: StaticString = #fileID, line: UInt32 = #line, _ body: @escaping (sending Double) -> Void) {
+        self.init(
+            makeClosure: make_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y,
+            body: body,
+            fileID: fileID,
+            line: line
+        )
+    }
+}
+
+@_expose(wasm, "invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y")
+@_cdecl("invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y")
+public func _invoke_swift_closure_BridgeJSRuntimeTests_20BridgeJSRuntimeTestssSd_y(_ boxPtr: UnsafeMutableRawPointer, _ param0: Float64) -> Void {
+    #if arch(wasm32)
+    let closure = Unmanaged<_BridgeJSTypedClosureBox<(sending Double) -> Void>>.fromOpaque(boxPtr).takeUnretainedValue().closure
+    closure(Double.bridgeJSLiftParameter(param0))
+    #else
+    fatalError("Only available on WebAssembly")
+    #endif
+}
+
 #if arch(wasm32)
 @_extern(wasm, module: "bjs", name: "invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestsy_13DataProcessorP")
 fileprivate func invoke_js_callback_BridgeJSRuntimeTests_20BridgeJSRuntimeTestsy_13DataProcessorP_extern(_ callback: Int32) -> Int32
@@ -11296,22 +11602,144 @@ func _$jsRoundTripFeatureFlag(_ flag: FeatureFlag) throws(JSException) -> Featur
 
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_runAsyncWorks")
-fileprivate func bjs_runAsyncWorks_extern() -> Int32
+fileprivate func bjs_runAsyncWorks_extern(_ resolveRef: Int32, _ rejectRef: Int32) -> Void
 #else
-fileprivate func bjs_runAsyncWorks_extern() -> Int32 {
+fileprivate func bjs_runAsyncWorks_extern(_ resolveRef: Int32, _ rejectRef: Int32) -> Void {
     fatalError("Only available on WebAssembly")
 }
 #endif
-@inline(never) fileprivate func bjs_runAsyncWorks() -> Int32 {
-    return bjs_runAsyncWorks_extern()
+@inline(never) fileprivate func bjs_runAsyncWorks(_ resolveRef: Int32, _ rejectRef: Int32) -> Void {
+    return bjs_runAsyncWorks_extern(resolveRef, rejectRef)
 }
 
-func _$runAsyncWorks() throws(JSException) -> JSPromise {
-    let ret = bjs_runAsyncWorks()
-    if let error = _swift_js_take_exception() {
-        throw error
+func _$runAsyncWorks() async throws(JSException) -> Void {
+    try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<() -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        bjs_runAsyncWorks(resolveRef, rejectRef)
     }
-    return JSPromise.bridgeJSLiftReturn(ret)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_jsAsyncRoundTripVoid")
+fileprivate func bjs_jsAsyncRoundTripVoid_extern(_ resolveRef: Int32, _ rejectRef: Int32) -> Void
+#else
+fileprivate func bjs_jsAsyncRoundTripVoid_extern(_ resolveRef: Int32, _ rejectRef: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_jsAsyncRoundTripVoid(_ resolveRef: Int32, _ rejectRef: Int32) -> Void {
+    return bjs_jsAsyncRoundTripVoid_extern(resolveRef, rejectRef)
+}
+
+func _$jsAsyncRoundTripVoid() async throws(JSException) -> Void {
+    try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<() -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        bjs_jsAsyncRoundTripVoid(resolveRef, rejectRef)
+    }
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_jsAsyncRoundTripNumber")
+fileprivate func bjs_jsAsyncRoundTripNumber_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Float64) -> Void
+#else
+fileprivate func bjs_jsAsyncRoundTripNumber_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_jsAsyncRoundTripNumber(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Float64) -> Void {
+    return bjs_jsAsyncRoundTripNumber_extern(resolveRef, rejectRef, v)
+}
+
+func _$jsAsyncRoundTripNumber(_ v: Double) async throws(JSException) -> Double {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending Double) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        let vValue = v.bridgeJSLowerParameter()
+        bjs_jsAsyncRoundTripNumber(resolveRef, rejectRef, vValue)
+    }
+    return resolved
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_jsAsyncRoundTripBool")
+fileprivate func bjs_jsAsyncRoundTripBool_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void
+#else
+fileprivate func bjs_jsAsyncRoundTripBool_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_jsAsyncRoundTripBool(_ resolveRef: Int32, _ rejectRef: Int32, _ v: Int32) -> Void {
+    return bjs_jsAsyncRoundTripBool_extern(resolveRef, rejectRef, v)
+}
+
+func _$jsAsyncRoundTripBool(_ v: Bool) async throws(JSException) -> Bool {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending Bool) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        let vValue = v.bridgeJSLowerParameter()
+        bjs_jsAsyncRoundTripBool(resolveRef, rejectRef, vValue)
+    }
+    return resolved
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_jsAsyncRoundTripString")
+fileprivate func bjs_jsAsyncRoundTripString_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ vBytes: Int32, _ vLength: Int32) -> Void
+#else
+fileprivate func bjs_jsAsyncRoundTripString_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ vBytes: Int32, _ vLength: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_jsAsyncRoundTripString(_ resolveRef: Int32, _ rejectRef: Int32, _ vBytes: Int32, _ vLength: Int32) -> Void {
+    return bjs_jsAsyncRoundTripString_extern(resolveRef, rejectRef, vBytes, vLength)
+}
+
+func _$jsAsyncRoundTripString(_ v: String) async throws(JSException) -> String {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending String) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        v.bridgeJSWithLoweredParameter { (vBytes, vLength) in
+            bjs_jsAsyncRoundTripString(resolveRef, rejectRef, vBytes, vLength)
+        }
+    }
+    return resolved
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_fetchWeatherData")
+fileprivate func bjs_fetchWeatherData_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ cityBytes: Int32, _ cityLength: Int32) -> Void
+#else
+fileprivate func bjs_fetchWeatherData_extern(_ resolveRef: Int32, _ rejectRef: Int32, _ cityBytes: Int32, _ cityLength: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_fetchWeatherData(_ resolveRef: Int32, _ rejectRef: Int32, _ cityBytes: Int32, _ cityLength: Int32) -> Void {
+    return bjs_fetchWeatherData_extern(resolveRef, rejectRef, cityBytes, cityLength)
+}
+
+func _$fetchWeatherData(_ city: String) async throws(JSException) -> WeatherData {
+    let resolved = try await _bjs_awaitPromise(makeResolveClosure: {
+            JSTypedClosure<(sending WeatherData) -> Void>($0)
+        }, makeRejectClosure: {
+            JSTypedClosure<(sending JSValue) -> Void>($0)
+        }) { resolveRef, rejectRef in
+        city.bridgeJSWithLoweredParameter { (cityBytes, cityLength) in
+            bjs_fetchWeatherData(resolveRef, rejectRef, cityBytes, cityLength)
+        }
+    }
+    return resolved
 }
 
 #if arch(wasm32)
@@ -11492,6 +11920,133 @@ func _$JsGreeter_changeName(_ self: JSObject, _ name: String) throws(JSException
     }
 }
 
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_WeatherData_temperature_get")
+fileprivate func bjs_WeatherData_temperature_get_extern(_ self: Int32) -> Float64
+#else
+fileprivate func bjs_WeatherData_temperature_get_extern(_ self: Int32) -> Float64 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_WeatherData_temperature_get(_ self: Int32) -> Float64 {
+    return bjs_WeatherData_temperature_get_extern(self)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_WeatherData_description_get")
+fileprivate func bjs_WeatherData_description_get_extern(_ self: Int32) -> Int32
+#else
+fileprivate func bjs_WeatherData_description_get_extern(_ self: Int32) -> Int32 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_WeatherData_description_get(_ self: Int32) -> Int32 {
+    return bjs_WeatherData_description_get_extern(self)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_WeatherData_humidity_get")
+fileprivate func bjs_WeatherData_humidity_get_extern(_ self: Int32) -> Float64
+#else
+fileprivate func bjs_WeatherData_humidity_get_extern(_ self: Int32) -> Float64 {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_WeatherData_humidity_get(_ self: Int32) -> Float64 {
+    return bjs_WeatherData_humidity_get_extern(self)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_WeatherData_temperature_set")
+fileprivate func bjs_WeatherData_temperature_set_extern(_ self: Int32, _ newValue: Float64) -> Void
+#else
+fileprivate func bjs_WeatherData_temperature_set_extern(_ self: Int32, _ newValue: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_WeatherData_temperature_set(_ self: Int32, _ newValue: Float64) -> Void {
+    return bjs_WeatherData_temperature_set_extern(self, newValue)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_WeatherData_description_set")
+fileprivate func bjs_WeatherData_description_set_extern(_ self: Int32, _ newValueBytes: Int32, _ newValueLength: Int32) -> Void
+#else
+fileprivate func bjs_WeatherData_description_set_extern(_ self: Int32, _ newValueBytes: Int32, _ newValueLength: Int32) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_WeatherData_description_set(_ self: Int32, _ newValueBytes: Int32, _ newValueLength: Int32) -> Void {
+    return bjs_WeatherData_description_set_extern(self, newValueBytes, newValueLength)
+}
+
+#if arch(wasm32)
+@_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs_WeatherData_humidity_set")
+fileprivate func bjs_WeatherData_humidity_set_extern(_ self: Int32, _ newValue: Float64) -> Void
+#else
+fileprivate func bjs_WeatherData_humidity_set_extern(_ self: Int32, _ newValue: Float64) -> Void {
+    fatalError("Only available on WebAssembly")
+}
+#endif
+@inline(never) fileprivate func bjs_WeatherData_humidity_set(_ self: Int32, _ newValue: Float64) -> Void {
+    return bjs_WeatherData_humidity_set_extern(self, newValue)
+}
+
+func _$WeatherData_temperature_get(_ self: JSObject) throws(JSException) -> Double {
+    let selfValue = self.bridgeJSLowerParameter()
+    let ret = bjs_WeatherData_temperature_get(selfValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return Double.bridgeJSLiftReturn(ret)
+}
+
+func _$WeatherData_description_get(_ self: JSObject) throws(JSException) -> String {
+    let selfValue = self.bridgeJSLowerParameter()
+    let ret = bjs_WeatherData_description_get(selfValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return String.bridgeJSLiftReturn(ret)
+}
+
+func _$WeatherData_humidity_get(_ self: JSObject) throws(JSException) -> Double {
+    let selfValue = self.bridgeJSLowerParameter()
+    let ret = bjs_WeatherData_humidity_get(selfValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+    return Double.bridgeJSLiftReturn(ret)
+}
+
+func _$WeatherData_temperature_set(_ self: JSObject, _ newValue: Double) throws(JSException) -> Void {
+    let selfValue = self.bridgeJSLowerParameter()
+    let newValueValue = newValue.bridgeJSLowerParameter()
+    bjs_WeatherData_temperature_set(selfValue, newValueValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+}
+
+func _$WeatherData_description_set(_ self: JSObject, _ newValue: String) throws(JSException) -> Void {
+    let selfValue = self.bridgeJSLowerParameter()
+    newValue.bridgeJSWithLoweredParameter { (newValueBytes, newValueLength) in
+        bjs_WeatherData_description_set(selfValue, newValueBytes, newValueLength)
+    }
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+}
+
+func _$WeatherData_humidity_set(_ self: JSObject, _ newValue: Double) throws(JSException) -> Void {
+    let selfValue = self.bridgeJSLowerParameter()
+    let newValueValue = newValue.bridgeJSLowerParameter()
+    bjs_WeatherData_humidity_set(selfValue, newValueValue)
+    if let error = _swift_js_take_exception() {
+        throw error
+    }
+}
+
 #if arch(wasm32)
 @_extern(wasm, module: "BridgeJSRuntimeTests", name: "bjs__WeirdClass_init")
 fileprivate func bjs__WeirdClass_init_extern() -> Int32
diff --git a/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json b/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json
index 842bcff24..c8c25c492 100644
--- a/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json
+++ b/Tests/BridgeJSRuntimeTests/Generated/JavaScript/BridgeJS.json
@@ -49,7 +49,8 @@
                         "width" : "word"
                       }
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -97,7 +98,8 @@
                     "double" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -145,7 +147,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -202,7 +205,8 @@
                         "width" : "word"
                       }
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : true
               }
@@ -250,7 +254,8 @@
                     "double" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : true
               }
@@ -298,7 +303,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : true
               }
@@ -591,7 +597,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -641,7 +648,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -684,7 +692,8 @@
                     "swiftHeapObject" : {
                       "_0" : "Greeter"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -724,7 +733,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -2931,7 +2941,8 @@
                       "string" : {
 
                       }
-                    }
+                    },
+                    "sendingParameters" : false
                   },
                   "useJSTypedClosure" : false
                 }
@@ -3017,7 +3028,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3059,7 +3071,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3100,7 +3113,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3151,7 +3165,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3199,7 +3214,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3246,7 +3262,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3282,7 +3299,8 @@
                       },
                       "_1" : "null"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3318,7 +3336,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3362,7 +3381,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3409,7 +3429,8 @@
                             "width" : "word"
                           }
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3455,7 +3476,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3497,7 +3519,8 @@
                     "bool" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3533,7 +3556,8 @@
                     "bool" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3572,7 +3596,8 @@
                         "width" : "word"
                       }
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3607,7 +3632,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3648,7 +3674,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3697,7 +3724,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3745,7 +3773,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3792,7 +3821,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3828,7 +3858,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3866,7 +3897,8 @@
                     "swiftProtocol" : {
                       "_0" : "DataProcessor"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3902,7 +3934,8 @@
                         "swiftProtocol" : {
                           "_0" : "DataProcessor"
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -3927,7 +3960,8 @@
                     "swiftProtocol" : {
                       "_0" : "DataProcessor"
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -3968,7 +4002,8 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -10604,7 +10639,8 @@
                           },
                           "_1" : "null"
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
@@ -13606,7 +13642,8 @@
                     "string" : {
 
                     }
-                  }
+                  },
+                  "sendingParameters" : false
                 },
                 "useJSTypedClosure" : false
               }
@@ -13656,7 +13693,8 @@
                 "string" : {
 
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -13708,7 +13746,8 @@
                     "width" : "word"
                   }
                 }
-              }
+              },
+              "sendingParameters" : false
             },
             "useJSTypedClosure" : false
           }
@@ -16372,6 +16411,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsIntArrayLength",
                 "parameters" : [
                   {
@@ -16400,6 +16444,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripIntArray",
                 "parameters" : [
                   {
@@ -16432,6 +16481,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripNumberArray",
                 "parameters" : [
                   {
@@ -16458,6 +16512,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripStringArray",
                 "parameters" : [
                   {
@@ -16484,6 +16543,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripBoolArray",
                 "parameters" : [
                   {
@@ -16510,6 +16574,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripJSValueArray",
                 "parameters" : [
                   {
@@ -16536,6 +16605,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripJSObjectArray",
                 "parameters" : [
                   {
@@ -16562,6 +16636,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripJSClassArray",
                 "parameters" : [
                   {
@@ -16588,6 +16667,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalIntArray",
                 "parameters" : [
                   {
@@ -16630,6 +16714,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalStringArray",
                 "parameters" : [
                   {
@@ -16666,6 +16755,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalBoolArray",
                 "parameters" : [
                   {
@@ -16702,6 +16796,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalJSValueArray",
                 "parameters" : [
                   {
@@ -16738,6 +16837,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalJSObjectArray",
                 "parameters" : [
                   {
@@ -16774,6 +16878,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalJSClassArray",
                 "parameters" : [
                   {
@@ -16810,6 +16919,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsSumNumberArray",
                 "parameters" : [
                   {
@@ -16832,6 +16946,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsCreateNumberArray",
                 "parameters" : [
 
@@ -16847,6 +16966,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "runJsArraySupportTests",
                 "parameters" : [
 
@@ -16879,6 +17003,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsApplyVoid",
                 "parameters" : [
                   {
@@ -16897,7 +17026,8 @@
                             "void" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -16911,6 +17041,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsApplyBool",
                 "parameters" : [
                   {
@@ -16929,7 +17064,8 @@
                             "bool" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -16943,6 +17079,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsApplyInt",
                 "parameters" : [
                   {
@@ -16982,7 +17123,8 @@
                                 "width" : "word"
                               }
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -16999,6 +17141,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsApplyDouble",
                 "parameters" : [
                   {
@@ -17029,7 +17176,8 @@
                             "double" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17043,6 +17191,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsApplyString",
                 "parameters" : [
                   {
@@ -17073,7 +17226,8 @@
                             "string" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17087,6 +17241,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsApplyJSObject",
                 "parameters" : [
                   {
@@ -17117,7 +17276,8 @@
                             "jsObject" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17131,6 +17291,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsMakeIntToInt",
                 "parameters" : [
                   {
@@ -17169,13 +17334,19 @@
                             "width" : "word"
                           }
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsMakeDoubleToDouble",
                 "parameters" : [
                   {
@@ -17205,13 +17376,19 @@
                         "double" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsMakeStringToString",
                 "parameters" : [
                   {
@@ -17241,13 +17418,19 @@
                         "string" : {
 
                         }
-                      }
+                      },
+                      "sendingParameters" : false
                     },
                     "useJSTypedClosure" : false
                   }
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsCallTwice",
                 "parameters" : [
                   {
@@ -17284,7 +17467,8 @@
                             "void" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17301,6 +17485,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsCallBinary",
                 "parameters" : [
                   {
@@ -17337,7 +17526,8 @@
                                 "width" : "word"
                               }
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17354,6 +17544,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsCallTriple",
                 "parameters" : [
                   {
@@ -17398,7 +17593,8 @@
                                 "width" : "word"
                               }
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17415,6 +17611,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsCallAfterRelease",
                 "parameters" : [
                   {
@@ -17433,7 +17634,8 @@
                             "void" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17447,6 +17649,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsOptionalInvoke",
                 "parameters" : [
                   {
@@ -17467,7 +17674,8 @@
                                 "bool" : {
 
                                 }
-                              }
+                              },
+                              "sendingParameters" : false
                             },
                             "useJSTypedClosure" : true
                           }
@@ -17484,6 +17692,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsStoreClosure",
                 "parameters" : [
                   {
@@ -17502,7 +17715,8 @@
                             "void" : {
 
                             }
-                          }
+                          },
+                          "sendingParameters" : false
                         },
                         "useJSTypedClosure" : true
                       }
@@ -17516,6 +17730,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsCallStoredClosure",
                 "parameters" : [
 
@@ -17527,6 +17746,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsHeapCount",
                 "parameters" : [
 
@@ -17541,6 +17765,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "runJsClosureSupportTests",
                 "parameters" : [
 
@@ -17573,6 +17802,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "runJsDefaultArgumentTests",
                 "parameters" : [
 
@@ -17605,6 +17839,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripDictionaryInt",
                 "parameters" : [
                   {
@@ -17637,6 +17876,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripDictionaryBool",
                 "parameters" : [
                   {
@@ -17663,6 +17907,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripDictionaryDouble",
                 "parameters" : [
                   {
@@ -17689,6 +17938,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripDictionaryJSObject",
                 "parameters" : [
                   {
@@ -17715,6 +17969,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripDictionaryJSValue",
                 "parameters" : [
                   {
@@ -17741,6 +18000,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripDictionaryDoubleArray",
                 "parameters" : [
                   {
@@ -17822,6 +18086,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripVoid",
             "parameters" : [
 
@@ -17833,6 +18102,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripNumber",
             "parameters" : [
               {
@@ -17851,6 +18125,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripBool",
             "parameters" : [
               {
@@ -17869,6 +18148,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripString",
             "parameters" : [
               {
@@ -17887,6 +18171,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripJSValue",
             "parameters" : [
               {
@@ -17905,6 +18194,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsThrowOrVoid",
             "parameters" : [
               {
@@ -17923,6 +18217,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsThrowOrNumber",
             "parameters" : [
               {
@@ -17941,6 +18240,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsThrowOrBool",
             "parameters" : [
               {
@@ -17959,6 +18263,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsThrowOrString",
             "parameters" : [
               {
@@ -17977,6 +18286,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsRoundTripFeatureFlag",
             "parameters" : [
               {
@@ -17997,17 +18311,135 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "runAsyncWorks",
             "parameters" : [
 
+            ],
+            "returnType" : {
+              "void" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "jsAsyncRoundTripVoid",
+            "parameters" : [
+
+            ],
+            "returnType" : {
+              "void" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "jsAsyncRoundTripNumber",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "double" : {
+
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "double" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "jsAsyncRoundTripBool",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "bool" : {
+
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "bool" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "jsAsyncRoundTripString",
+            "parameters" : [
+              {
+                "name" : "v",
+                "type" : {
+                  "string" : {
+
+                  }
+                }
+              }
+            ],
+            "returnType" : {
+              "string" : {
+
+              }
+            }
+          },
+          {
+            "effects" : {
+              "isAsync" : true,
+              "isStatic" : false,
+              "isThrows" : true
+            },
+            "name" : "fetchWeatherData",
+            "parameters" : [
+              {
+                "name" : "city",
+                "type" : {
+                  "string" : {
+
+                  }
+                }
+              }
             ],
             "returnType" : {
               "jsObject" : {
-                "_0" : "JSPromise"
+                "_0" : "WeatherData"
               }
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "jsName" : "$jsWeirdFunction",
             "name" : "_jsWeirdFunction",
             "parameters" : [
@@ -18020,6 +18452,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "from" : "global",
             "name" : "parseInt",
             "parameters" : [
@@ -18092,6 +18529,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "greet",
                 "parameters" : [
 
@@ -18103,6 +18545,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "changeName",
                 "parameters" : [
                   {
@@ -18137,6 +18584,70 @@
 
             ]
           },
+          {
+            "getters" : [
+              {
+                "name" : "temperature",
+                "type" : {
+                  "double" : {
+
+                  }
+                }
+              },
+              {
+                "name" : "description",
+                "type" : {
+                  "string" : {
+
+                  }
+                }
+              },
+              {
+                "name" : "humidity",
+                "type" : {
+                  "double" : {
+
+                  }
+                }
+              }
+            ],
+            "methods" : [
+
+            ],
+            "name" : "WeatherData",
+            "setters" : [
+              {
+                "functionName" : "temperature_set",
+                "name" : "temperature",
+                "type" : {
+                  "double" : {
+
+                  }
+                }
+              },
+              {
+                "functionName" : "description_set",
+                "name" : "description",
+                "type" : {
+                  "string" : {
+
+                  }
+                }
+              },
+              {
+                "functionName" : "humidity_set",
+                "name" : "humidity",
+                "type" : {
+                  "double" : {
+
+                  }
+                }
+              }
+            ],
+            "staticMethods" : [
+
+            ]
+          },
           {
             "constructor" : {
               "parameters" : [
@@ -18149,6 +18660,11 @@
             "jsName" : "$WeirdClass",
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "jsName" : "method-with-dashes",
                 "name" : "method_with_dashes",
                 "parameters" : [
@@ -18187,6 +18703,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "value",
                 "parameters" : [
 
@@ -18204,6 +18725,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "create",
                 "parameters" : [
                   {
@@ -18222,6 +18748,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "value",
                 "parameters" : [
 
@@ -18233,6 +18764,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "makeDefault",
                 "parameters" : [
 
@@ -18244,6 +18780,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "jsName" : "with-dashes",
                 "name" : "with_dashes",
                 "parameters" : [
@@ -18315,6 +18856,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "bark",
                 "parameters" : [
 
@@ -18326,6 +18872,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "getIsCat",
                 "parameters" : [
 
@@ -18376,6 +18927,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsTranslatePoint",
             "parameters" : [
               {
@@ -18438,6 +18994,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripInt",
                 "parameters" : [
                   {
@@ -18462,6 +19023,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripUInt",
                 "parameters" : [
                   {
@@ -18486,6 +19052,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripInt8",
                 "parameters" : [
                   {
@@ -18510,6 +19081,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripUInt8",
                 "parameters" : [
                   {
@@ -18534,6 +19110,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripInt16",
                 "parameters" : [
                   {
@@ -18558,6 +19139,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripUInt16",
                 "parameters" : [
                   {
@@ -18582,6 +19168,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripInt32",
                 "parameters" : [
                   {
@@ -18606,6 +19197,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripUInt32",
                 "parameters" : [
                   {
@@ -18630,6 +19226,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripInt64",
                 "parameters" : [
                   {
@@ -18654,6 +19255,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripUInt64",
                 "parameters" : [
                   {
@@ -18678,6 +19284,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "runJsIntegerTypesSupportTests",
                 "parameters" : [
 
@@ -18760,6 +19371,11 @@
             ],
             "methods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "concatNumbers",
                 "parameters" : [
                   {
@@ -18792,6 +19408,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "concatLabels",
                 "parameters" : [
                   {
@@ -18818,6 +19439,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "firstLabel",
                 "parameters" : [
                   {
@@ -18889,6 +19515,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "makeJSClassWithArrayMembers",
                 "parameters" : [
                   {
@@ -19002,6 +19633,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsFunctionWithPackageAccess",
             "parameters" : [
 
@@ -19013,6 +19649,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsFunctionWithPublicAccess",
             "parameters" : [
 
@@ -19024,6 +19665,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsFunctionWithInternalAccess",
             "parameters" : [
 
@@ -19035,6 +19681,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsFunctionWithFilePrivateAccess",
             "parameters" : [
 
@@ -19046,6 +19697,11 @@
             }
           },
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "name" : "jsFunctionWithPrivateAccess",
             "parameters" : [
 
@@ -19079,6 +19735,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalNumberNull",
                 "parameters" : [
                   {
@@ -19113,6 +19774,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalNumberUndefined",
                 "parameters" : [
                   {
@@ -19147,6 +19813,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalStringNull",
                 "parameters" : [
                   {
@@ -19175,6 +19846,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalStringUndefined",
                 "parameters" : [
                   {
@@ -19203,6 +19879,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalJSValueArrayNull",
                 "parameters" : [
                   {
@@ -19239,6 +19920,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalJSValueArrayUndefined",
                 "parameters" : [
                   {
@@ -19275,6 +19961,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalStringToStringDictionaryNull",
                 "parameters" : [
                   {
@@ -19311,6 +20002,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalStringToStringDictionaryUndefined",
                 "parameters" : [
                   {
@@ -19347,6 +20043,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "runJsOptionalSupportTests",
                 "parameters" : [
 
@@ -19364,6 +20065,11 @@
       {
         "functions" : [
           {
+            "effects" : {
+              "isAsync" : false,
+              "isStatic" : false,
+              "isThrows" : true
+            },
             "from" : "global",
             "name" : "gc",
             "parameters" : [
@@ -19390,6 +20096,11 @@
             ],
             "staticMethods" : [
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripGreeter",
                 "parameters" : [
                   {
@@ -19408,6 +20119,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripUUID",
                 "parameters" : [
                   {
@@ -19426,6 +20142,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsRoundTripOptionalGreeter",
                 "parameters" : [
                   {
@@ -19454,6 +20175,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsConsumeLeakCheck",
                 "parameters" : [
                   {
@@ -19472,6 +20198,11 @@
                 }
               },
               {
+                "effects" : {
+                  "isAsync" : false,
+                  "isStatic" : false,
+                  "isThrows" : true
+                },
                 "name" : "jsConsumeOptionalLeakCheck",
                 "parameters" : [
                   {
diff --git a/Tests/BridgeJSRuntimeTests/bridge-js.d.ts b/Tests/BridgeJSRuntimeTests/bridge-js.d.ts
index e8533a3d8..635a783b8 100644
--- a/Tests/BridgeJSRuntimeTests/bridge-js.d.ts
+++ b/Tests/BridgeJSRuntimeTests/bridge-js.d.ts
@@ -26,6 +26,20 @@ export class JsGreeter {
 
 export function runAsyncWorks(): Promise<void>;
 
+// Async round-trip tests
+export function jsAsyncRoundTripVoid(): Promise<void>;
+export function jsAsyncRoundTripNumber(v: number): Promise<number>;
+export function jsAsyncRoundTripBool(v: boolean): Promise<boolean>;
+export function jsAsyncRoundTripString(v: string): Promise<string>;
+
+// Async fetch-like test with structured return type
+export interface WeatherData {
+    temperature: number;
+    description: string;
+    humidity: number;
+}
+export function fetchWeatherData(city: string): Promise<WeatherData>;
+
 // jsName tests
 export function $jsWeirdFunction(): number;
 
diff --git a/Tests/prelude.mjs b/Tests/prelude.mjs
index 8eb9a0270..8c652bc5c 100644
--- a/Tests/prelude.mjs
+++ b/Tests/prelude.mjs
@@ -119,6 +119,25 @@ export async function setupOptions(options, context) {
                 },
                 StaticBox,
                 Foo: ImportedFoo,
+                "fetchWeatherData": (city) => {
+                    return Promise.resolve({
+                        temperature: city === "London" ? 15.5 : 25.0,
+                        description: city === "London" ? "Cloudy" : "Sunny",
+                        humidity: city === "London" ? 80 : 40,
+                    });
+                },
+                "jsAsyncRoundTripVoid": () => {
+                    return Promise.resolve();
+                },
+                "jsAsyncRoundTripNumber": (v) => {
+                    return Promise.resolve(v);
+                },
+                "jsAsyncRoundTripBool": (v) => {
+                    return Promise.resolve(v);
+                },
+                "jsAsyncRoundTripString": (v) => {
+                    return Promise.resolve(v);
+                },
                 runAsyncWorks: async () => {
                     const exports = importsContext.getExports();
                     if (!exports) {