From 664fc0309e85f91a415e2b3788731b310015b7ed Mon Sep 17 00:00:00 2001
From: Charles Lyding <19598772+clydin@users.noreply.github.com>
Date: Thu, 13 Nov 2025 06:21:18 -0500
Subject: [PATCH] fix(@angular/build): ensure Vitest setup files are executed
 in order

This commit configures the Vitest runner to execute setup files in the order they are defined. This is crucial for ensuring that polyfills and the Angular TestBed are initialized in the correct sequence before any tests are run, preventing potential issues with the testing environment.
---
 .../unit-test/runners/vitest/plugins.ts       |  1 +
 .../e2e/tests/vitest/browser-playwright.ts    | 34 +++++++++++++++++++
 .../e2e/tests/vitest/browser-webdriverio.ts   | 33 ++++++++++++++++++
 3 files changed, 68 insertions(+)
 create mode 100644 tests/legacy-cli/e2e/tests/vitest/browser-playwright.ts
 create mode 100644 tests/legacy-cli/e2e/tests/vitest/browser-webdriverio.ts

diff --git a/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts b/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts
index c375d182750d..04554955cd18 100644
--- a/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts
+++ b/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts
@@ -119,6 +119,7 @@ export async function createVitestConfigPlugin(
           globals: true,
           // Default to `false` to align with the Karma/Jasmine experience.
           isolate: false,
+          sequence: { setupFiles: 'list' },
         },
         optimizeDeps: {
           noDiscovery: true,
diff --git a/tests/legacy-cli/e2e/tests/vitest/browser-playwright.ts b/tests/legacy-cli/e2e/tests/vitest/browser-playwright.ts
new file mode 100644
index 000000000000..9b22b81736e4
--- /dev/null
+++ b/tests/legacy-cli/e2e/tests/vitest/browser-playwright.ts
@@ -0,0 +1,34 @@
+import assert from 'node:assert/strict';
+import { applyVitestBuilder } from '../../utils/vitest';
+import { exec, ng } from '../../utils/process';
+import { installPackage } from '../../utils/packages';
+import { writeFile } from '../../utils/fs';
+
+export default async function (): Promise<void> {
+  await applyVitestBuilder();
+  await installPackage('playwright@1');
+  await installPackage('@vitest/browser-playwright@4');
+  await exec('npx', 'playwright', 'install', 'chromium', '--only-shell');
+
+  await ng('generate', 'component', 'my-comp');
+
+  await writeFile(
+    'src/setup1.ts',
+    `
+      import { getTestBed } from '@angular/core/testing';
+
+      getTestBed().configureTestingModule({});
+    `,
+  );
+
+  const { stdout } = await ng(
+    'test',
+    '--no-watch',
+    '--browsers',
+    'chromiumHeadless',
+    '--setup-files',
+    'src/setup1.ts',
+  );
+
+  assert.match(stdout, /2 passed/, 'Expected 2 tests to pass.');
+}
diff --git a/tests/legacy-cli/e2e/tests/vitest/browser-webdriverio.ts b/tests/legacy-cli/e2e/tests/vitest/browser-webdriverio.ts
new file mode 100644
index 000000000000..4ea1b913c3b0
--- /dev/null
+++ b/tests/legacy-cli/e2e/tests/vitest/browser-webdriverio.ts
@@ -0,0 +1,33 @@
+import assert from 'node:assert/strict';
+import { applyVitestBuilder } from '../../utils/vitest';
+import { ng } from '../../utils/process';
+import { installPackage } from '../../utils/packages';
+import { writeFile } from '../../utils/fs';
+
+export default async function (): Promise<void> {
+  await applyVitestBuilder();
+  await installPackage('webdriverio@9');
+  await installPackage('@vitest/browser-webdriverio@4');
+
+  await ng('generate', 'component', 'my-comp');
+
+  await writeFile(
+    'src/setup1.ts',
+    `
+    import { getTestBed } from '@angular/core/testing';
+
+    getTestBed().configureTestingModule({});
+  `,
+  );
+
+  const { stdout } = await ng(
+    'test',
+    '--no-watch',
+    '--browsers',
+    'chromeHeadless',
+    '--setup-files',
+    'src/setup1.ts',
+  );
+
+  assert.match(stdout, /2 passed/, 'Expected 2 tests to pass.');
+}