From a40cd47aa7ebccfbeeb26e397e03f1372aa10a55 Mon Sep 17 00:00:00 2001
From: Kristiyan Kostadinov <crisbeto@abv.bg>
Date: Thu, 2 Feb 2023 09:30:28 +0100
Subject: [PATCH] fix(migrations): avoid modifying testing modules without
 declarations (#48921)

Fixes that we were changing the testing modules that have no `declarations` unnecessarily, resulting in more formatting changes that users would have to clean up.

PR Close #48921
---
 .../standalone-migration/to-standalone.ts     |  5 ++++
 .../test/standalone_migration_spec.ts         | 28 +++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/packages/core/schematics/ng-generate/standalone-migration/to-standalone.ts b/packages/core/schematics/ng-generate/standalone-migration/to-standalone.ts
index d3f8694fcbb..ebfe985537f 100644
--- a/packages/core/schematics/ng-generate/standalone-migration/to-standalone.ts
+++ b/packages/core/schematics/ng-generate/standalone-migration/to-standalone.ts
@@ -437,6 +437,11 @@ function analyzeTestingModules(
 
   for (const obj of testObjects) {
     const declarations = extractDeclarationsFromTestObject(obj, typeChecker);
+
+    if (declarations.length === 0) {
+      continue;
+    }
+
     const importsProp = findLiteralProperty(obj, 'imports');
     const importElements = importsProp && hasNgModuleMetadataElements(importsProp) ?
         importsProp.initializer.elements :
diff --git a/packages/core/schematics/test/standalone_migration_spec.ts b/packages/core/schematics/test/standalone_migration_spec.ts
index 118ec261e16..8079be0d7e6 100644
--- a/packages/core/schematics/test/standalone_migration_spec.ts
+++ b/packages/core/schematics/test/standalone_migration_spec.ts
@@ -1043,6 +1043,34 @@ describe('standalone migration', () => {
     `));
   });
 
+  it('should not change testing objects with no declarations', async () => {
+    const initialContent = `
+      import {NgModule, Component} from '@angular/core';
+      import {TestBed} from '@angular/core/testing';
+      import {ButtonModule} from './button.module';
+      import {MatCardModule} from '@angular/material/card';
+
+      describe('bootrstrapping an app', () => {
+        it('should work', () => {
+          TestBed.configureTestingModule({
+            imports: [ButtonModule, MatCardModule]
+          });
+          const fixture = TestBed.createComponent(App);
+          expect(fixture.nativeElement.innerHTML).toBe('<hello>Hello</hello>');
+        });
+      });
+
+      @Component({template: 'hello'})
+      class App {}
+    `;
+
+    writeFile('app.spec.ts', initialContent);
+
+    await runMigration('convert-to-standalone');
+
+    expect(tree.readContent('app.spec.ts')).toBe(initialContent);
+  });
+
   it('should migrate tests with a component declared through Catalyst', async () => {
     writeFile('app.spec.ts', `
       import {NgModule, Component} from '@angular/core';