5 Things to Know About Migrating Angular Tests to Vitest (After Moving 20+ Repositories)

5 Things to Know About Migrating Angular Tests to Vitest (After Moving 20+ Repositories) Cristian Sifuentes \ 4 min read · Feb 24, 2026 I recently completed migrating the unit tests of more than 40 repositories that power a large Angular certification ecosystem to Vitest . This wasn't a toy migration.\ It involved real-world test suites, legacy Jasmine patterns, async RxJS flows, DOM-heavy component tests, and CI pipelines. What follows is not a tutorial. It's what actually changes --- and what doesn't --- when you move from Jasmine/Karma (or Jest) to Vitest in Angular 21+. Vitest Is 99% the Same Syntax --- And That's the Point Consider this test: it ( ' should create ' , () => { expect ( component ). toBeTruthy (); }); it ( ' should display four tabs ' , () => { const tabs = fixture . debugElement . queryAll ( By . css ( ' button ' )); expect ( tabs . length ). toBe ( 4 ); }); What framework is this? Jasmine\ Jest\ Vitest Answer: All of them. Modern JS testing ecosystems converged tow