ng-add support for Vitest browser providers doesn't work

Reproduce the issue with the listed ng new, ng add, Playwright install, and ng test steps. Compare the generated angular.json and tsconfig.spec.json with the documented browser-mode configuration, then inspect the ng-add support introduced by commit f80db6f. Done means ng add configures the browsers option so ng test runs in the Vitest browser environment rather than jsdom in Node.js.

Command

add

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

No response

Description

@angular/cli v21.2.0-next.0 added in https://github.com/angular/angular-cli/commit/f80db6fb714aa326f6ed03a8a51090ca59ad0955 add ng-add support for Vitest browser providers but it is not complete and does not actually work.

The schematic correctly adds the required packages and modifies tsconfig.spec.json but does not add the browsers option as documented at https://angular.dev/guide/testing/migrating-to-vitest#5-configure-browser-mode-optional.

Without this option the test doesn't actually run in browser environment and is still run in DOM emulation library within Node.js.

Minimal Reproduction

Repro steps:

1. ng new angular22dot2dot0next0 --ssr=false --style=scss --ai-config=none
2. ng add @vitest/browser-playwright
3. npx playwright install
4. Open app.spec.ts and add line to any test: console.log('RUNNING IN:', navigator.userAgent);
5. Run test via ng test
6. Observe the console outputs: RUNNING IN: Mozilla/5.0 (win32) AppleWebKit/537.36 (KHTML, like Gecko) jsdom/27.4.0
7. Test still runs in Node.js with DOM emulation, not in Vitest browser ❌

How to fix:

1. Open angular.json and change:

"test": {
  "builder": "@angular/build:unit-test"
}

to:

"test": {
  "builder": "@angular/build:unit-test",
  "options": {
    "browsers": ["chromium"]
  }
}

2. Run test via ng test
3. Observe actual Chrome for Testing window opens and Console outputs: RUNNING IN: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36
4. Test runs in Vitest browser 👍

Exception or Error

Your Environment

_                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/


Angular CLI       : 21.2.0-next.0
Node.js           : 24.13.0
Package Manager   : npm 11.6.2
Operating System  : win32 x64

Anything else relevant?

No response