cel-expr · copybara-service · Jun 9, 2025 · Jun 9, 2025
diff --git a/extensions/src/test/java/dev/cel/extensions/CelOptionalLibraryTest.java b/extensions/src/test/java/dev/cel/extensions/CelOptionalLibraryTest.java
@@ -913,6 +913,45 @@ public void traditionalIndex_onOptionalList_returnsOptionalEmpty() throws Except
    assertThat(result).isEqualTo(Optional.empty());
  }

+  @Test
+  // LHS
+  @TestParameters("{expression: 'optx.or(optional.of(1))'}")
+  @TestParameters("{expression: 'optx.orValue(1)'}")
+  // RHS
+  @TestParameters("{expression: 'optional.none().or(optx)'}")
+  @TestParameters("{expression: 'optional.none().orValue(optx)'}")
+  public void optionalChainedFunctions_lhsIsUnknown_returnsUnknown(String expression)
+      throws Exception {
+    Cel cel =
+        newCelBuilder()
+            .addVar("optx", OptionalType.create(SimpleType.INT))
+            .addVar("x", SimpleType.INT)
+            .build();
+    CelAbstractSyntaxTree ast = cel.compile(expression).getAst();
+
+    Object result = cel.createProgram(ast).eval();
+
+    assertThat(InterpreterUtil.isUnknown(result)).isTrue();
+  }
+
+  @Test
+  // LHS
+  @TestParameters("{expression: 'optional.of(1/0).or(optional.of(1))'}")
+  @TestParameters("{expression: 'optional.of(1/0).orValue(1)'}")
+  // RHS
+  @TestParameters("{expression: 'optional.none().or(optional.of(1/0))'}")
+  @TestParameters("{expression: 'optional.none().orValue(1/0)'}")
+  public void optionalChainedFunctions_lhsIsError_returnsError(String expression) throws Exception {
+    Cel cel =
+        newCelBuilder()
+            .addVar("optx", OptionalType.create(SimpleType.INT))
+            .addVar("x", SimpleType.INT)
+            .build();
+    CelAbstractSyntaxTree ast = cel.compile(expression).getAst();
+
+    assertThrows(CelEvaluationException.class, () -> cel.createProgram(ast).eval());
+  }
+
  @Test
  public void traditionalIndex_onOptionalList_returnsOptionalValue() throws Exception {
    Cel cel =

diff --git a/runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java b/runtime/src/main/java/dev/cel/runtime/DefaultInterpreter.java
@@ -680,30 +680,28 @@ private IntermediateResult evalType(ExecutionFrame frame, CelCall callExpr)

    private IntermediateResult evalOptionalOr(ExecutionFrame frame, CelCall callExpr)
        throws CelEvaluationException {
-      CelExpr lhsExpr = callExpr.target().get();
-      IntermediateResult lhsResult = evalInternal(frame, lhsExpr);
-      if (!(lhsResult.value() instanceof Optional)) {
-        throw CelEvaluationExceptionBuilder.newBuilder(
-                "expected optional value, found: %s", lhsResult.value())
-            .setErrorCode(CelErrorCode.INVALID_ARGUMENT)
-            .setMetadata(metadata, lhsExpr.id())
-            .build();
-      }
-
-      Optional<?> lhsOptionalValue = (Optional<?>) lhsResult.value();
-
-      if (lhsOptionalValue.isPresent()) {
-        // Short-circuit lhs if a value exists
-        return lhsResult;
-      }
-
-      return evalInternal(frame, callExpr.args().get(0));
+      return evalOptionalOrInternal(frame, callExpr, /* unwrapOptional= */ false);
    }

    private IntermediateResult evalOptionalOrValue(ExecutionFrame frame, CelCall callExpr)
        throws CelEvaluationException {
-      CelExpr lhsExpr = callExpr.target().get();
+      return evalOptionalOrInternal(frame, callExpr, /* unwrapOptional= */ true);
+    }
+
+    private IntermediateResult evalOptionalOrInternal(
+        ExecutionFrame frame, CelCall callExpr, boolean unwrapOptional)
+        throws CelEvaluationException {
+      CelExpr lhsExpr =
+          callExpr
+              .target()
+              .orElseThrow(
+                  () -> new IllegalStateException("Missing target for chained optional function"));
      IntermediateResult lhsResult = evalInternal(frame, lhsExpr);
+
+      if (isUnknownValue(lhsResult.value())) {
+        return lhsResult;
+      }
+
      if (!(lhsResult.value() instanceof Optional)) {
        throw CelEvaluationExceptionBuilder.newBuilder(
                "expected optional value, found: %s", lhsResult.value())
@@ -716,7 +714,7 @@ private IntermediateResult evalOptionalOrValue(ExecutionFrame frame, CelCall cal

      if (lhsOptionalValue.isPresent()) {
        // Short-circuit lhs if a value exists
-        return IntermediateResult.create(lhsOptionalValue.get());
+        return unwrapOptional ? IntermediateResult.create(lhsOptionalValue.get()) : lhsResult;
      }

      return evalInternal(frame, callExpr.args().get(0));