fix(@angular/build): prevent missing NgModule scope errors in unit tests

packages/angular/build/src/builders/application/options.ts

@@ -140,9 +140,9 @@ interface InternalOptions {
   disableCodeSplitting?: boolean;
 
   /**
-   * An array of files to restrict the TypeScript compilation root names to.
+   * An array of files to exclude from the TypeScript compilation root names.
    */
-  rootFiles?: string[];
+  excludeRootFiles?: string[];
 }
 
 /** Full set of options for `application` builder. */
@@ -456,7 +456,7 @@ export async function normalizeOptions(
     verbose,
     watch,
     progress = true,
-    rootFiles,
+    excludeRootFiles,
     externalPackages,
     namedChunks,
     budgets,
@@ -504,7 +504,7 @@ export async function normalizeOptions(
     workspaceRoot,
     entryPoints,
     disableCodeSplitting,
-    rootFiles: rootFiles?.map((file: string) => path.resolve(workspaceRoot, file)),
+    excludeRootFiles: excludeRootFiles?.map((file: string) => path.resolve(workspaceRoot, file)),
     optimizationOptions,
     outputOptions,
     outExtension,

packages/angular/build/src/builders/unit-test/runners/vitest/build-options.ts

@@ -21,6 +21,8 @@ import { type NormalizedUnitTestBuilderOptions, injectTestingPolyfills } from '.
 import { findTests, getTestEntrypoints } from '../../test-discovery';
 import { RunnerOptions } from '../api';
 
+const DEFAULT_TEST_PATTERNS = ['**/*.spec.ts', '**/*.test.ts'];
+
 /**
  * Creates the virtual file contents to initialize the Angular testing environment (TestBed).
  *
@@ -210,14 +212,7 @@ export async function getVitestBuildOptions(
     removeTestExtension: true,
   });
 
-  const rootFiles = [...testFiles];
-  if (providersFile) {
-    rootFiles.push(providersFile);
-  }
-
   if (setupFiles?.length) {
-    rootFiles.push(...setupFiles);
-
     const setupEntryPoints = getTestEntrypoints(setupFiles, {
       projectSourceRoot,
       workspaceRoot,
@@ -230,6 +225,34 @@ export async function getVitestBuildOptions(
     }
   }
 
+  let excludeRootFiles: string[] | undefined;
+  const isDefaultInclude =
+    exclude.length === 0 &&
+    include.length === DEFAULT_TEST_PATTERNS.length &&
+    include.every((val: string) => DEFAULT_TEST_PATTERNS.includes(val));
+
+  if (!isDefaultInclude) {
+    const allTestFiles = await findTests(
+      DEFAULT_TEST_PATTERNS,
+      [],
+      workspaceRoot,
+      projectSourceRoot,
+    );
+    const testFilesSet = new Set(testFiles);
+    if (providersFile) {
+      testFilesSet.add(toPosixPath(providersFile));
+    }
+
+    if (setupFiles?.length) {
+      for (const setupFile of setupFiles) {
+        testFilesSet.add(toPosixPath(setupFile));
+      }
+    }
+
+    const unselectedTestFiles = allTestFiles.filter((file) => !testFilesSet.has(file));
+    excludeRootFiles = unselectedTestFiles.length > 0 ? unselectedTestFiles : undefined;
+  }
+
   // The Angular compiler facade must be loaded in a dedicated setup file before TestBed initialization.
   // This ensures the compiler facade is published before 'init-testbed' or any shared code-split chunks
   // (such as those from a configured 'providersFile') are evaluated.
@@ -267,7 +290,7 @@ export async function getVitestBuildOptions(
     optimization: false,
     namedChunks: false,
     entryPoints,
-    rootFiles,
+    excludeRootFiles,
     // Vitest's Node-based module loading emulation (vite-node) is not fully spec compliant and lacks
     // live ESM bindings across chunk boundaries. This can cause uninitialized exports or break mocking.
     // Disabling code splitting avoids shared chunks, but increases build and coverage memory/time.

packages/angular/build/src/builders/unit-test/tests/options/include_spec.ts

@@ -110,5 +110,77 @@ describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
       const { result } = await harness.executeOnce();
       expect(result?.success).toBeTrue();
     });
+
+    it('should compile NgModule declared components when using include in an NgModule app', async () => {
+      await harness.writeFiles({
+        'src/tsconfig.spec.json': JSON.stringify({
+          extends: '../tsconfig.json',
+          compilerOptions: {
+            outDir: '../out-tsc/spec',
+            types: ['vitest/globals'],
+          },
+          include: ['**/*.d.ts', '**/*.ts'],
+        }),
+        'src/app/app.module.ts': `
+          import { NgModule } from '@angular/core';
+          import { BrowserModule } from '@angular/platform-browser';
+          import { RouterModule } from '@angular/router';
+          import { AppComponent } from './app.component';
+
+          @NgModule({
+            declarations: [AppComponent],
+            imports: [BrowserModule, RouterModule],
+          })
+          export class AppModule {}
+        `,
+        'src/app/app.component.ts': `
+          import { Component } from '@angular/core';
+
+          @Component({
+            selector: 'app-root',
+            standalone: false,
+            templateUrl: './app.component.html',
+          })
+          export class AppComponent {}
+        `,
+        'src/app/app.component.html': '<router-outlet />',
+        'src/app/app.component.spec.ts': `
+          import { TestBed } from '@angular/core/testing';
+          import { RouterModule } from '@angular/router';
+          import { AppComponent } from './app.component';
+
+          describe('AppComponent', () => {
+            beforeEach(async () => {
+              await TestBed.configureTestingModule({
+                imports: [RouterModule.forRoot([])],
+                declarations: [AppComponent],
+              }).compileComponents();
+            });
+
+            it('should create the app', () => {
+              const fixture = TestBed.createComponent(AppComponent);
+              const app = fixture.componentInstance;
+              expect(app).toBeTruthy();
+            });
+          });
+        `,
+        'src/app/broken.service.spec.ts': `
+          // This test has a TypeScript type error that would fail compilation if compiled
+          const invalidNumber: number = 'not a number';
+          describe('BrokenService', () => {
+            it('should fail compilation', () => {
+              expect(invalidNumber).toBe(1);
+            });
+          });`,
+      });
+
+      harness.useTarget('test', {
+        ...BASE_OPTIONS,
+        include: ['src/app/app.component.spec.ts'],
+      });
+
+      const { result } = await harness.executeOnce();
+      expect(result?.success).toBeTrue();
+    });
   });
 });

packages/angular/build/src/builders/unit-test/tests/options/tsconfig_spec.ts

@@ -55,5 +55,68 @@ describeBuilder(execute, UNIT_TEST_BUILDER_INFO, (harness) => {
       expect(result?.success).toBeFalse();
       expectLog(logs, `The specified tsConfig file 'random/tsconfig.spec.json' does not exist.`);
     });
+
+    it('should compile NgModule declared components when tsConfig includes application files', async () => {
+      await harness.writeFiles({
+        'src/tsconfig.spec.json': JSON.stringify({
+          extends: '../tsconfig.json',
+          compilerOptions: {
+            outDir: '../out-tsc/spec',
+            types: ['vitest/globals'],
+          },
+          include: ['**/*.d.ts', '**/*.ts'],
+        }),
+        'src/app/app.module.ts': `
+          import { NgModule } from '@angular/core';
+          import { BrowserModule } from '@angular/platform-browser';
+          import { RouterModule } from '@angular/router';
+          import { AppComponent } from './app.component';
+
+          @NgModule({
+            declarations: [AppComponent],
+            imports: [BrowserModule, RouterModule],
+          })
+          export class AppModule {}
+        `,
+        'src/app/app.component.ts': `
+          import { Component } from '@angular/core';
+
+          @Component({
+            selector: 'app-root',
+            standalone: false,
+            templateUrl: './app.component.html',
+          })
+          export class AppComponent {}
+        `,
+        'src/app/app.component.html': '<router-outlet />',
+        'src/app/app.component.spec.ts': `
+          import { TestBed } from '@angular/core/testing';
+          import { RouterModule } from '@angular/router';
+          import { AppComponent } from './app.component';
+
+          describe('AppComponent', () => {
+            beforeEach(async () => {
+              await TestBed.configureTestingModule({
+                imports: [RouterModule.forRoot([])],
+                declarations: [AppComponent],
+              }).compileComponents();
+            });
+
+            it('should create the app', () => {
+              const fixture = TestBed.createComponent(AppComponent);
+              const app = fixture.componentInstance;
+              expect(app).toBeTruthy();
+            });
+          });
+        `,
+      });
+
+      harness.useTarget('test', {
+        ...BASE_OPTIONS,
+      });
+
+      const { result } = await harness.executeOnce();
+      expect(result?.success).toBeTrue();
+    });
   });
 });

packages/angular/build/src/tools/angular/compilation/compiler-options.ts

@@ -21,6 +21,7 @@ export interface CompilerOptionOverrides {
   includeTestMetadata?: boolean;
   customConditions?: string[];
   rootFiles?: string[];
+  excludeRootFiles?: string[];
   declarationMap?: boolean;
   compilationMode?: 'full' | 'partial';
   paths?: Record<string, string[]>;

packages/angular/build/src/tools/angular/compilation/typescript-compilation.ts

@@ -66,14 +66,24 @@ export abstract class TypeScriptCompilation extends AngularCompilation {
       const rootFilesSet = new Set(
         compilerOptionOverrides.rootFiles.map((file) => canonicalizePath(toPosixPath(file))),
       );
+
       for (const file of originalRootNames) {
         if (/\.d\.[cm]?ts$/i.test(file)) {
           rootFilesSet.add(canonicalizePath(toPosixPath(file)));
         }
       }
+
       rootNames = [...rootFilesSet];
     }
 
+    if (compilerOptionOverrides?.excludeRootFiles?.length) {
+      const excludeSet = new Set(
+        compilerOptionOverrides.excludeRootFiles.map((file) => canonicalizePath(toPosixPath(file))),
+      );
+
+      rootNames = rootNames.filter((file) => !excludeSet.has(canonicalizePath(toPosixPath(file))));
+    }
+
     const { compilerOptions, warnings } = transformCompilerOptions(
       ts,
       originalCompilerOptions,

packages/angular/build/src/tools/esbuild/angular/compiler-plugin.ts

@@ -61,7 +61,7 @@ export interface CompilerPluginOptions {
   externalRuntimeStyles?: boolean;
   instrumentForCoverage?: (request: string) => boolean;
   templateUpdates?: Map<string, string>;
-  rootFiles?: string[];
+  excludeRootFiles?: string[];
 }
 
 // eslint-disable-next-line max-lines-per-function
@@ -330,7 +330,7 @@ export function createCompilerPlugin(
               instrumentForCoverage: !!pluginOptions.instrumentForCoverage,
               includeTestMetadata: !!pluginOptions.includeTestMetadata,
               customConditions: build.initialOptions.conditions,
-              rootFiles: pluginOptions.rootFiles,
+              excludeRootFiles: pluginOptions.excludeRootFiles,
             },
           );
 

packages/angular/build/src/tools/esbuild/compiler-plugin-options.ts

@@ -28,7 +28,7 @@ export function createCompilerPluginOptions(
     externalRuntimeStyles,
     instrumentForCoverage,
     optimizationOptions,
-    rootFiles,
+    excludeRootFiles,
   } = options;
   const incremental = !!options.watch;
 
@@ -46,6 +46,6 @@ export function createCompilerPluginOptions(
     instrumentForCoverage,
     templateUpdates,
     includeTestMetadata: !optimizationOptions.scripts,
-    rootFiles,
+    excludeRootFiles,
   };
 }