vitest requires zone.js when angular is moving away from this

[rajinder-yadav]

Which @angular/* package(s) are the source of the bug?

Don't known / other

Is this a regression?

Yes

Description

vitest doesn't work with a zoneless angular app, product the following error:

Error: NG0908: In this configuration Angular requires Zone.js

Please provide a link to a minimal reproduction of the bug

No response

Please provide the exception or error you saw

1. create a zoneless angular app
1. add vitest 
1. see runtime error

ref: https://angular.dev/guide/testing/unit-tests

Please provide the environment you discovered this bug in (run ng version)

Angular CLI: 20.3.3
Node: 22.20.0
Package Manager: pnpm 10.15.0
OS: linux x64
    

Angular: <error>

Package                      Version
------------------------------------
@angular-devkit/architect    0.2003.3
@angular-devkit/core         20.3.3
@angular-devkit/schematics   20.3.3
@schematics/angular          20.3.3

Anything else?

No response

[atscott]

Vitest not require zone.js but does use zone change detection by default prior to v21.

You can update your tests to use Zoneless change detection by default in tests with the providersFile option:

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

Line 162 in 6b97932

"providersFile": {

Zoneless is the default in 21 so closing this as expected behavior prior to v21 and fixed in 21 onwards.