microsoft · DanielRosenwasser · Jan 21, 2020 · Jan 14, 2020
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -2346,7 +2346,7 @@ namespace ts {
                            }
                        }
                        else {
-                            if (moduleSymbol.exports && moduleSymbol.exports.has(InternalSymbolName.Default)) {
+                            if (moduleSymbol.exports?.has(InternalSymbolName.Default)) {
                                error(
                                    name,
                                    Diagnostics.Module_0_has_no_exported_member_1_Did_you_mean_to_use_import_1_from_0_instead,
@@ -2355,7 +2355,7 @@ namespace ts {
                                );
                            }
                            else {
-                                error(name, Diagnostics.Module_0_has_no_exported_member_1, moduleName, declarationName);
+                                reportNonExportedMember(name, declarationName, moduleSymbol, moduleName);
                            }
                        }
                    }
@@ -2364,6 +2364,27 @@ namespace ts {
            }
        }

+        function reportNonExportedMember(name: Identifier, declarationName: string, moduleSymbol: Symbol, moduleName: string): void {
+            const localSymbol = moduleSymbol.valueDeclaration.locals?.get(name.escapedText);
+            const exports = moduleSymbol.exports;
+
+            if (localSymbol) {
+                const exportedSymbol = exports && !exports.has(InternalSymbolName.ExportEquals)
+                    ? find(symbolsToArray(exports), symbol => !!getSymbolIfSameReference(symbol, localSymbol))
+                    : undefined;
+                const diagnostic = exportedSymbol
+                    ? error(name, Diagnostics.Module_0_declares_1_locally_but_it_is_exported_as_2, moduleName, declarationName, symbolToString(exportedSymbol))
+                    : error(name, Diagnostics.Module_0_declares_1_locally_but_it_is_not_exported, moduleName, declarationName);
+
+                addRelatedInfo(diagnostic,
+                    createDiagnosticForNode(localSymbol.valueDeclaration, Diagnostics._0_is_declared_here, declarationName)
+                );
+            }
+            else {
+                error(name, Diagnostics.Module_0_has_no_exported_member_1, moduleName, declarationName);
+            }
+        }
+
        function getTargetOfImportSpecifier(node: ImportSpecifier, dontResolveAlias: boolean): Symbol | undefined {
            const resolved = getExternalModuleMember(node.parent.parent.parent, node, dontResolveAlias);
            if (resolved && node.parent.parent.isTypeOnly) {

diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
@@ -1765,6 +1765,14 @@
        "category": "Error",
        "code": 2458
    },
+    "Module '{0}' declares '{1}' locally, but it is not exported.": {
+        "category": "Error",
+        "code": 2459
+    },
+    "Module '{0}' declares '{1}' locally, but it is exported as '{2}'.": {
+        "category": "Error",
+        "code": 2460
+    },
    "Type '{0}' is not an array type.": {
        "category": "Error",
        "code": 2461

diff --git a/tests/baselines/reference/es6ImportNamedImportNoNamedExports.errors.txt b/tests/baselines/reference/es6ImportNamedImportNoNamedExports.errors.txt
@@ -1,5 +1,5 @@
-tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(1,10): error TS2305: Module '"./es6ImportNamedImportNoNamedExports_0"' has no exported member 'a'.
-tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(2,10): error TS2305: Module '"./es6ImportNamedImportNoNamedExports_0"' has no exported member 'a'.
+tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(1,10): error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.
+tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(2,10): error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.


 ==== tests/cases/compiler/es6ImportNamedImportNoNamedExports_0.ts (0 errors) ====
@@ -9,7 +9,9 @@ tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts(2,10): error TS2305
 ==== tests/cases/compiler/es6ImportNamedImportNoNamedExports_1.ts (2 errors) ====
    import { a } from "./es6ImportNamedImportNoNamedExports_0";
             ~
-!!! error TS2305: Module '"./es6ImportNamedImportNoNamedExports_0"' has no exported member 'a'.
+!!! error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.
+!!! related TS2728 tests/cases/compiler/es6ImportNamedImportNoNamedExports_0.ts:1:5: 'a' is declared here.
    import { a as x } from "./es6ImportNamedImportNoNamedExports_0";
             ~
-!!! error TS2305: Module '"./es6ImportNamedImportNoNamedExports_0"' has no exported member 'a'.
+!!! error TS2459: Module '"./es6ImportNamedImportNoNamedExports_0"' declares 'a' locally, but it is not exported.
+!!! related TS2728 tests/cases/compiler/es6ImportNamedImportNoNamedExports_0.ts:1:5: 'a' is declared here.
diff --git a/tests/baselines/reference/importNonExportedMember.errors.txt b/tests/baselines/reference/importNonExportedMember.errors.txt
@@ -0,0 +1,14 @@
+tests/cases/compiler/b.ts(1,15): error TS2460: Module '"./a"' declares 'bar' locally, but it is exported as 'baz'.
+
+
+==== tests/cases/compiler/a.ts (0 errors) ====
+    declare function foo(): any
+    declare function bar(): any;
+    export { foo, bar as baz };
+
+==== tests/cases/compiler/b.ts (1 errors) ====
+    import { foo, bar } from "./a";
+                  ~~~
+!!! error TS2460: Module '"./a"' declares 'bar' locally, but it is exported as 'baz'.
+!!! related TS2728 tests/cases/compiler/a.ts:2:18: 'bar' is declared here.
+
diff --git a/tests/baselines/reference/importNonExportedMember.js b/tests/baselines/reference/importNonExportedMember.js
@@ -0,0 +1,17 @@
+//// [tests/cases/compiler/importNonExportedMember.ts] ////
+
+//// [a.ts]
+declare function foo(): any
+declare function bar(): any;
+export { foo, bar as baz };
+
+//// [b.ts]
+import { foo, bar } from "./a";
+
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;
+//// [b.js]
+"use strict";
+exports.__esModule = true;
diff --git a/tests/baselines/reference/importNonExportedMember.symbols b/tests/baselines/reference/importNonExportedMember.symbols
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/a.ts ===
+declare function foo(): any
+>foo : Symbol(foo, Decl(a.ts, 0, 0))
+
+declare function bar(): any;
+>bar : Symbol(bar, Decl(a.ts, 0, 27))
+
+export { foo, bar as baz };
+>foo : Symbol(foo, Decl(a.ts, 2, 8))
+>bar : Symbol(bar, Decl(a.ts, 0, 27))
+>baz : Symbol(baz, Decl(a.ts, 2, 13))
+
+=== tests/cases/compiler/b.ts ===
+import { foo, bar } from "./a";
+>foo : Symbol(foo, Decl(b.ts, 0, 8))
+>bar : Symbol(bar, Decl(b.ts, 0, 13))
+
diff --git a/tests/baselines/reference/importNonExportedMember.types b/tests/baselines/reference/importNonExportedMember.types
@@ -0,0 +1,17 @@
+=== tests/cases/compiler/a.ts ===
+declare function foo(): any
+>foo : () => any
+
+declare function bar(): any;
+>bar : () => any
+
+export { foo, bar as baz };
+>foo : () => any
+>bar : () => any
+>baz : () => any
+
+=== tests/cases/compiler/b.ts ===
+import { foo, bar } from "./a";
+>foo : () => any
+>bar : any
+
diff --git a/tests/baselines/reference/importNonExportedMember1.errors.txt b/tests/baselines/reference/importNonExportedMember1.errors.txt
@@ -0,0 +1,14 @@
+tests/cases/compiler/b.ts(1,10): error TS2459: Module '"./a"' declares 'bar' locally, but it is not exported.
+
+
+==== tests/cases/compiler/a.ts (0 errors) ====
+    declare function foo(): any
+    declare function bar(): any;
+    export { foo };
+
+==== tests/cases/compiler/b.ts (1 errors) ====
+    import { bar } from "./a";
+             ~~~
+!!! error TS2459: Module '"./a"' declares 'bar' locally, but it is not exported.
+!!! related TS2728 tests/cases/compiler/a.ts:2:18: 'bar' is declared here.
+
diff --git a/tests/baselines/reference/importNonExportedMember1.js b/tests/baselines/reference/importNonExportedMember1.js
@@ -0,0 +1,17 @@
+//// [tests/cases/compiler/importNonExportedMember1.ts] ////
+
+//// [a.ts]
+declare function foo(): any
+declare function bar(): any;
+export { foo };
+
+//// [b.ts]
+import { bar } from "./a";
+
+
+//// [a.js]
+"use strict";
+exports.__esModule = true;
+//// [b.js]
+"use strict";
+exports.__esModule = true;
diff --git a/tests/baselines/reference/importNonExportedMember1.symbols b/tests/baselines/reference/importNonExportedMember1.symbols
@@ -0,0 +1,14 @@
+=== tests/cases/compiler/a.ts ===
+declare function foo(): any
+>foo : Symbol(foo, Decl(a.ts, 0, 0))
+
+declare function bar(): any;
+>bar : Symbol(bar, Decl(a.ts, 0, 27))
+
+export { foo };
+>foo : Symbol(foo, Decl(a.ts, 2, 8))
+
+=== tests/cases/compiler/b.ts ===
+import { bar } from "./a";
+>bar : Symbol(bar, Decl(b.ts, 0, 8))
+
diff --git a/tests/baselines/reference/importNonExportedMember1.types b/tests/baselines/reference/importNonExportedMember1.types
@@ -0,0 +1,14 @@
+=== tests/cases/compiler/a.ts ===
+declare function foo(): any
+>foo : () => any
+
+declare function bar(): any;
+>bar : () => any
+
+export { foo };
+>foo : () => any
+
+=== tests/cases/compiler/b.ts ===
+import { bar } from "./a";
+>bar : any
+
diff --git a/tests/cases/compiler/importNonExportedMember.ts b/tests/cases/compiler/importNonExportedMember.ts
@@ -0,0 +1,7 @@
+// @filename: a.ts
+declare function foo(): any
+declare function bar(): any;
+export { foo, bar as baz };
+
+// @filename: b.ts
+import { foo, bar } from "./a";
diff --git a/tests/cases/compiler/importNonExportedMember1.ts b/tests/cases/compiler/importNonExportedMember1.ts
@@ -0,0 +1,7 @@
+// @filename: a.ts
+declare function foo(): any
+declare function bar(): any;
+export { foo };
+
+// @filename: b.ts
+import { bar } from "./a";