Migrate unit tests from Jasmine/Karma to a modern stack

Open
  • Is something wrong?
#6,173 3 comments 1 reaction 1 assignee View on GitHub

Maintainers usually reply within 1 day

@alexandrevryghem is already working on this.

Since Oct 2, 2026.

Assessment

This issue has not been assessed yet.

Description

claimed: Atmire code task dependencies needs analysis testing framework

Is your feature request related to a problem? Please describe.

Upgrade to Angular v18 was finalized in DSpace 9.0 (DSpace/dspace-angular#3304). However, Jasmine/Karma is still used for unit tests but, as noted in the issue, Karma is deprecated.

Angular v21 declared stable support for Vitest. This is also the Angular team's default choice for new projects in v21+ (moreover, Angular team also provided a guide on Migrating from Karma to Vitest, so the migration can be semi-automated.)

I'd like us to discuss and plan a migration away from Karma to a modern test runner. From what I can see, the most commonly mentioned options are:

  • Vitest (default in Angular >=v21)
  • Jest (has been around longer)
  • Web Test Runner (runs tests in a real browser rather than Node/jsdom)

Vitest and Jest are both a test runner and a testing library, so they replace both Karma + Jasmine stack. Web Test Runner replaces only Karma (uses bult-in Mocha framework support, but has Jasmine adapter web-test-runner-jasmine).

Also, check out Vitest's Comparisons with Other Test Runners page.

What about Jasmine? Cypress?

Just to avoid confusion: Karma is only the test runner (it launches the browser and reports results). Jasmine is the testing framework we actually write tests with (spyOn etc.).

Both Vitest and Jest support Jasmine-style syntax (and maintain compatibility with most Jasmine functions)

We also use Cypress as the e2e tool (so it's not related to unit tests)

Describe the solution you'd like

This ticket is to discuss and plan a migration away from Karma.

Describe alternatives or workarounds you've considered

We are currently still using Karma via @angular-devkit/build-angular and @angular-builders/custom-webpack:karma. This works for now, but it depends on a deprecated package

Changing the unit test runner while on Angular v20 could make a future v21 upgrade smoother

Additional information

Karma/Jasmine and Angular Timeline
  • Angular v16 declared that Karma was deprecated.
    • This version added experimental support for Jest, and Web Test Runner [source]
  • Angular v20 added experimental support for Vitest [source]
  • Angular v21 declared Vitest as the primary test runner (and stable), replacing Karma [source]

Vitest has gained significant traction recently. According to npm trends, Vitest downloads surpassed Jest around April 2026, and now seem to be 2x higher (Jest was first published in NPM 15 years ago, Vitest 5 years ago).

Questions for the Community
  • Any strong opinions (for or against) any particular test runner?
  • Any other alternatives we should consider?
  • Has anyone already migrated a large Angular project from Karma? If so, what challenges did you face?
  • Does anyone have experience with Vitest in a large Angular monorepo?
  • Are there any DSpace-specific testing needs that might complicate migration?
References

Additional sources not directly mentioned in this issue:

Dominant language
TypeScript
Stars
180
Forks
577
Avg merge
2d 1h
Merged PRs (30d)
100

Getting set up

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from DSpace/dspace-angular

All issues in DSpace/dspace-angular

Similar issues

More TypeScript issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.