fix(@ngtools/webpack): only remove moduleId in decorators

Prior to this we were removing all mentions of moduleId, which is invalid if the users want
to use it themselves. Now we only removes it if its in a decorator. There might be a slight
regression with people using static const objects instead of object literals in their
decorators but this shuold not happen often and even less often with moduleId.

Fixes #5509.

packages/@ngtools/webpack/src/loader.spec.ts

@@ -11,16 +11,28 @@ describe('@ngtools/webpack', () => {
         host.writeFile('/file.ts', `
           export const obj = { moduleId: 123 };
           export const obj2 = { moduleId: 123, otherValue: 1 };
-          export const obj2 = { otherValue: 1, moduleId: 123 };
+          export const obj3 = { otherValue: 1, moduleId: 123 };
+        `, false);
+        host.writeFile('/file2.ts', `
+          @SomeDecorator({ moduleId: 123 }) class CLS {}
+          @SomeDecorator({ moduleId: 123, otherValue1: 1 }) class CLS2 {}
+          @SomeDecorator({ otherValue2: 2, moduleId: 123, otherValue3: 3 }) class CLS3 {}
+          @SomeDecorator({ otherValue4: 4, moduleId: 123 }) class CLS4 {}
         `, false);
 
-        const program = ts.createProgram(['/file.ts'], {}, host);
+        const program = ts.createProgram(['/file.ts', '/file2.ts'], {}, host);
 
         const refactor = new TypeScriptFileRefactor('/file.ts', host, program);
         removeModuleIdOnlyForTesting(refactor);
+        expect(refactor.sourceText).not.toMatch(/obj = \{\s+};/);
+        expect(refactor.sourceText).not.toMatch(/\{\s*otherValue: 1\s*};/);
 
-        expect(refactor.sourceText).toMatch(/obj = \{\s+};/);
-        expect(refactor.sourceText).toMatch(/obj2 = \{\s*otherValue: 1\s*};/);
+        const refactor2 = new TypeScriptFileRefactor('/file2.ts', host, program);
+        removeModuleIdOnlyForTesting(refactor2);
+        expect(refactor2.sourceText).toMatch(/\(\{\s+}\)/);
+        expect(refactor2.sourceText).toMatch(/\(\{\s*otherValue1: 1\s*}\)/);
+        expect(refactor2.sourceText).toMatch(/\(\{\s*otherValue2: 2\s*,\s*otherValue3: 3\s*}\)/);
+        expect(refactor2.sourceText).toMatch(/\(\{\s*otherValue4: 4\s*}\)/);
       });
     });
   });

packages/@ngtools/webpack/src/loader.ts

@@ -241,7 +241,10 @@ export function removeModuleIdOnlyForTesting(refactor: TypeScriptFileRefactor) {
 function _removeModuleId(refactor: TypeScriptFileRefactor) {
   const sourceFile = refactor.sourceFile;
 
-  refactor.findAstNodes(sourceFile, ts.SyntaxKind.ObjectLiteralExpression, true)
+  refactor.findAstNodes(sourceFile, ts.SyntaxKind.Decorator, true)
+    .reduce((acc, node) => {
+      return acc.concat(refactor.findAstNodes(node, ts.SyntaxKind.ObjectLiteralExpression, true));
+    }, [])
     // Get all their property assignments.
     .filter((node: ts.ObjectLiteralExpression) => {
       return node.properties.some(prop => {
@@ -254,8 +257,9 @@ function _removeModuleId(refactor: TypeScriptFileRefactor) {
         return prop.kind == ts.SyntaxKind.PropertyAssignment
             && _getContentOfKeyLiteral(sourceFile, prop.name) == 'moduleId';
       })[0];
-      // get the trailing comma
-      const moduleIdCommaProp = moduleIdProp.parent.getChildAt(1).getChildren()[1];
+      // Get the trailing comma.
+      const moduleIdCommaProp = moduleIdProp.parent
+        ? moduleIdProp.parent.getChildAt(1).getChildren()[1] : null;
       refactor.removeNodes(moduleIdProp, moduleIdCommaProp);
     });
 }