Feature Request: Support Vitest

[NateRadebaugh]

Describe the feature or problem you'd like to solve

I know jest is supported, but is Vitest? The syntax is very similar.

[satanTime]

Hey @NateRadebaugh,

personally, I don't have experience with Vitest, but if it's very similar it should work.
The only thing ng-mocks requires is angular, beforeEach, afterEach, beforeAll and afterAll.

So if Vitest is providing them, ng-mocks should be compatible with it.

[Tallyb]

it needs the equivalent of jest-preset-angular

[satanTime]

Hi @Tallyb, do you have an example of a project I could take a look at to understand how Vitest works and where ng-mocks can fit?

[Tallyb]

https://github.com/Tallyb/ng-mocks-vitest @satanTime

[satanTime]

Thank you a lot and Merry Christmas! I'll take a look next days.

[mionelTX]

Could you please consider adding Vitest support to ng-mocks? It's 2025, and Vitest has become increasingly popular due to its speed, native ESM support, and seamless integration with Vite. With Angular 18 adopting Vite as its default build system, many developers are transitioning to Vitest for testing. Tools like AnalogJS have made integrating Vitest into Angular projects straightforward. Adding support for Vitest in ng-mocks would greatly benefit the community.

[Tallyb]

I have only checked services and not rendering (we are using storybook for testing UI), and it works just fine. It is basically using the analogjs plugin for compiling angular.
Feel free to consult this repo https://github.com/Tallyb/angular-realworld-example-app as reference.

[ytchenak]

I noted that angular 20 added experimental vitest browser support to unit-testing: see PR angular/angular-cli#30168

[undsoft]

Note, that if you are using MockComponent and you may encounter errors related to missing providers such as No provider found for x.

You can fix them by adjusting your vite.config.ts:

    server: {
      deps: {
        inline: ['ng-mocks'],
      },
    },

[GipHub123]

I tried running my test cases with Vitest, but I had previously run them successfully using Karma.

Test Files  302 failed | 1942 passed (2244)
   Tests  494 failed | 7757 passed (8251)
   Errors  92 errors
   Start at  14:46:27
   Duration  1640.51s (transform 392.43s, setup 94.65s, collect 3782.75s, tests 980.44s, environment 10146.52s, prepare 908ms)

Log was filled with weird error like.

Failed to construct 'PointerEvent': member view is not of type Window
Error: Component '_XXXComponent' has unresolved metadata. Please call `await TestBed.compileComponents()` before running this test.
Error: [vitest-worker]: Closing rpc while "fetch" was pending

Vitest seems quite slow—it took around 27 minutes, whereas the same tests ran in about 6-7 minutes with Karma.
Note that I'm not sure if problems are ng-mocks / vitest / jsdom or test case related 😐