fix(ngcc): better detection of end of decorator expression (#33192)

for removal of decorator from __decorate calls.

FW-1629 #resolve

PR Close #33192

packages/compiler-cli/ngcc/src/rendering/esm_rendering_formatter.ts

@@ -99,9 +99,17 @@ export class EsmRenderingFormatter implements RenderingFormatter {
         } else {
           nodesToRemove.forEach(node => {
             // remove any trailing comma
-            const end = (output.slice(node.getEnd(), node.getEnd() + 1) === ',') ?
+            const nextSibling = getNextSiblingInArray(node, items);
-                node.getEnd() + 1 :
+            let end: number;
-                node.getEnd();
+
+            if (nextSibling !== null &&
+                output.slice(nextSibling.getFullStart() - 1, nextSibling.getFullStart()) === ',') {
+              end = nextSibling.getFullStart() - 1 + nextSibling.getLeadingTriviaWidth();
+            } else if (output.slice(node.getEnd(), node.getEnd() + 1) === ',') {
+              end = node.getEnd() + 1;
+            } else {
+              end = node.getEnd();
+            }
             output.remove(node.getFullStart(), end);
           });
         }
@@ -214,3 +222,8 @@ function generateImportString(
   const importAs = importPath ? importManager.generateNamedImport(importPath, importName) : null;
   return importAs ? `${importAs.moduleImport}.${importAs.symbol}` : `${importName}`;
 }
+
+function getNextSiblingInArray<T extends ts.Node>(node: T, array: ts.NodeArray<T>): T|null {
+  const index = array.indexOf(node);
+  return index !== -1 && array.length > index + 1 ? array[index + 1] : null;
+}

packages/compiler-cli/ngcc/test/rendering/esm_rendering_formatter_spec.ts

@@ -288,6 +288,28 @@ A.decorators = [
                  .toContain(`{ type: Directive, args: [{ selector: '[c]' }] }`);
            });
 
+        it('should handle a decorator with a trailing comment', () => {
+          const text = `
+import {Directive} from '@angular/core';
+export class A {}
+A.decorators = [
+  { type: Directive, args: [{ selector: '[a]' }] },
+  { type: OtherA }
+];
+          `;
+          const file = {name: _('/node_modules/test-package/index.js'), contents: text};
+          const {decorationAnalyses, sourceFile, renderer} = setup([file]);
+          const output = new MagicString(text);
+          const compiledClass =
+              decorationAnalyses.get(sourceFile) !.compiledClasses.find(c => c.name === 'A') !;
+          const decorator = compiledClass.decorators ![0];
+          const decoratorsToRemove = new Map<ts.Node, ts.Node[]>();
+          decoratorsToRemove.set(decorator.node.parent !, [decorator.node]);
+          renderer.removeDecorators(output, decoratorsToRemove);
+          // The decorator should have been removed correctly.
+          expect(output.toString()).toContain('A.decorators = [ { type: OtherA }');
+        });
+
 
         it('should delete the decorator (and its container if there are no other decorators left) that was matched in the analysis',
            () => {