fix(migrations): error in standalone migration when non-array value i…

…s used as declarations in TestBed (#54122)

Adds some logic to skip over `TestBed.configureTestingModule` calls where the `declarations` aren't initialized to an array. We can't migrate these cases, because test migrations don't have access to the Angular compiler. Previously the migration would throw a runtime error.

PR Close #54122

packages/core/schematics/ng-generate/standalone-migration/to-standalone.ts

@@ -442,15 +442,24 @@ export function findTestObjectsToMigrate(sourceFile: ts.SourceFile, typeChecker:
 
   if (testBedImport || catalystImport) {
     sourceFile.forEachChild(function walk(node) {
-      if (ts.isCallExpression(node) && node.arguments.length > 0 &&
+      const isObjectLiteralCall = ts.isCallExpression(node) && node.arguments.length > 0 &&
           // `arguments[0]` is the testing module config.
-          ts.isObjectLiteralExpression(node.arguments[0])) {
-        if ((testBedImport && ts.isPropertyAccessExpression(node.expression) &&
-             node.expression.name.text === 'configureTestingModule' &&
-             isReferenceToImport(typeChecker, node.expression.expression, testBedImport)) ||
-            (catalystImport && ts.isIdentifier(node.expression) &&
-             isReferenceToImport(typeChecker, node.expression, catalystImport))) {
-          testObjects.push(node.arguments[0]);
+          ts.isObjectLiteralExpression(node.arguments[0]);
+      const config = isObjectLiteralCall ? node.arguments[0] as ts.ObjectLiteralExpression : null;
+      const isTestBedCall = isObjectLiteralCall &&
+          (testBedImport && ts.isPropertyAccessExpression(node.expression) &&
+           node.expression.name.text === 'configureTestingModule' &&
+           isReferenceToImport(typeChecker, node.expression.expression, testBedImport));
+      const isCatalystCall = isObjectLiteralCall &&
+          (catalystImport && ts.isIdentifier(node.expression) &&
+           isReferenceToImport(typeChecker, node.expression, catalystImport));
+
+      if ((isTestBedCall || isCatalystCall) && config) {
+        const declarations = findLiteralProperty(config, 'declarations');
+        if (declarations && ts.isPropertyAssignment(declarations) &&
+            ts.isArrayLiteralExpression(declarations.initializer) &&
+            declarations.initializer.elements.length > 0) {
+          testObjects.push(config);
         }
       }
 

packages/core/schematics/test/standalone_migration_spec.ts

@@ -1428,6 +1428,48 @@ describe('standalone migration', () => {
       `));
      });
 
+  it('should not migrate `configureTestingModule` with a non-array expression in the `declarations` field',
+     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';
+
+          function setup(declarations: any[], imports: any[]) {
+            TestBed.configureTestingModule({
+              declarations: declarations,
+              imports,
+            });
+            return TestBed.createComponent(App);
+          }
+
+          describe('bootstrapping an app', () => {
+            it('should work', () => {
+              const fixture = setup([App, Hello], [ButtonModule, MatCardModule]);
+              expect(fixture.nativeElement.innerHTML).toBe('<hello>Hello</hello>');
+            });
+
+            it('should work in a different way', () => {
+              const fixture = setup([App, Hello], [MatCardModule]);
+              expect(fixture.nativeElement.innerHTML).toBe('<hello>Hello</hello>');
+            });
+          });
+
+          @Component({selector: 'hello', template: 'Hello'})
+          class Hello {}
+
+          @Component({template: '<hello></hello>'})
+          class App {}
+        `;
+
+       writeFile('app.spec.ts', initialContent);
+
+       await runMigration('convert-to-standalone');
+
+       expect(tree.readContent('app.spec.ts')).toBe(initialContent);
+     });
+
   it('should not migrate modules with a `bootstrap` array', async () => {
     const initialModule = `
       import {NgModule, Component} from '@angular/core';