fix(rosetta): allow only property assignments in object literals (#3065)

We'll report on anything else that JavaScript allows you to do (methods, getters, etc).

Fixes #3061.

---

By submitting this pull request, I confirm that my contribution is made under the terms of the [Apache 2.0 license].

[Apache 2.0 license]: https://www.apache.org/licenses/LICENSE-2.0

packages/jsii-rosetta/lib/languages/default.ts

@@ -143,6 +143,15 @@ export abstract class DefaultVisitor<C> implements AstHandler<C> {
    *     - It's not a struct (render as key-value map)
    */
   public objectLiteralExpression(node: ts.ObjectLiteralExpression, context: AstRenderer<C>): OTree {
+    // If any of the elements of the objectLiteralExpression are not a literal property
+    // assignment, report them. We can't support those.
+    const unsupported = node.properties.filter(
+      (p) => !ts.isPropertyAssignment(p) && !ts.isShorthandPropertyAssignment(p),
+    );
+    for (const unsup of unsupported) {
+      context.report(unsup, `Use of ${ts.SyntaxKind[unsup.kind]} in an object literal is not supported.`);
+    }
+
     const type = context.inferredTypeOfExpression(node);
 
     let isUnknownType = !type;

packages/jsii-rosetta/test/translate.test.ts

@@ -55,3 +55,23 @@ test('rejects ?? operator', () => {
 
   expect(subject.diagnostics[0].messageText).toContain('QuestionQuestionToken');
 });
+
+test('rejects function declarations in object literals', () => {
+  const snippet: TypeScriptSnippet = {
+    completeSource: 'const x = { method() { return 1; } }',
+    where: '@aws-cdk.aws-apigateway-README-snippet4',
+    visibleSource: 'const x = { method() { return 1; } }',
+    parameters: { lit: 'test/integ.restapi-import.lit.ts' },
+    strict: false,
+  };
+
+  // WHEN
+  const subject = new SnippetTranslator(snippet, {
+    includeCompilerDiagnostics: true,
+  });
+  subject.renderUsing(new PythonVisitor());
+
+  expect(subject.diagnostics[0].messageText).toContain(
+    'Use of MethodDeclaration in an object literal is not supported',
+  );
+});