fix(@angular/build): add update option to vitest unit-test builder

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

@@ -127,6 +127,7 @@ export async function normalizeOptions(
       : [],
     dumpVirtualFiles: options.dumpVirtualFiles,
     listTests: options.listTests,
+    update: options.update ?? false,
     runnerConfig:
       typeof runnerConfig === 'string'
         ? runnerConfig.length === 0

packages/angular/build/src/builders/unit-test/options_spec.ts

@@ -0,0 +1,85 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import { mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { normalizeOptions } from './options';
+import type { Schema as UnitTestBuilderOptions } from './schema';
+
+function createMockContext(workspaceRoot: string) {
+  return {
+    workspaceRoot,
+    target: { project: 'test-project', target: 'test', configuration: '' },
+    logger: { warn: () => {}, info: () => {}, error: () => {}, debug: () => {} },
+    getProjectMetadata: async (_projectName: string) => ({
+      root: '.',
+      sourceRoot: 'src',
+    }),
+    getBuilderNameForTarget: async () => '@angular/build:application',
+  };
+}
+
+describe('normalizeOptions', () => {
+  let workspaceRoot: string;
+
+  beforeEach(async () => {
+    workspaceRoot = await mkdtemp(join(tmpdir(), 'angular-cli-options-spec-'));
+    // Write a minimal package.json so cache normalization works
+    await writeFile(join(workspaceRoot, 'package.json'), '{}');
+    // Create a tsconfig.spec.json so tsConfig resolution succeeds
+    await mkdir(join(workspaceRoot, 'src'), { recursive: true });
+    await writeFile(join(workspaceRoot, 'tsconfig.spec.json'), '{}');
+  });
+
+  afterEach(async () => {
+    await rm(workspaceRoot, { recursive: true, force: true });
+  });
+
+  it('should set update to false by default', async () => {
+    const options: UnitTestBuilderOptions = {};
+    const context = createMockContext(workspaceRoot);
+
+    const normalized = await normalizeOptions(
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      context as any,
+      'test-project',
+      options,
+    );
+
+    expect(normalized.update).toBeFalse();
+  });
+
+  it('should set update to true when update option is true', async () => {
+    const options: UnitTestBuilderOptions = { update: true };
+    const context = createMockContext(workspaceRoot);
+
+    const normalized = await normalizeOptions(
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      context as any,
+      'test-project',
+      options,
+    );
+
+    expect(normalized.update).toBeTrue();
+  });
+
+  it('should set update to false when update option is explicitly false', async () => {
+    const options: UnitTestBuilderOptions = { update: false };
+    const context = createMockContext(workspaceRoot);
+
+    const normalized = await normalizeOptions(
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      context as any,
+      'test-project',
+      options,
+    );
+
+    expect(normalized.update).toBeFalse();
+  });
+});

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

@@ -240,6 +240,7 @@ export class VitestExecutor implements TestExecutor {
       runnerConfig,
       projectSourceRoot,
       cacheOptions,
+      update,
     } = this.options;
     const projectName = this.projectName;
 
@@ -355,6 +356,7 @@ export class VitestExecutor implements TestExecutor {
       cache: cacheOptions.enabled ? undefined : (false as const),
       testNamePattern: this.options.filter,
       watch,
+      ...(update ? { update } : {}),
       ...(typeof ui === 'boolean' ? { ui } : {}),
       ...debugOptions,
     };

packages/angular/build/src/builders/unit-test/schema.json

@@ -262,6 +262,11 @@
       "type": "boolean",
       "description": "Shows build progress information in the console. Defaults to the `progress` setting of the specified `buildTarget`."
     },
+    "update": {
+      "type": "boolean",
+      "description": "Updates existing snapshots when they fail instead of failing the test. Only available for the Vitest runner.",
+      "default": false
+    },
     "listTests": {
       "type": "boolean",
       "description": "Lists all discovered test files and exits the process without building or executing the tests.",