angular-testing

Writing unit tests for Angular v20 signal components involves configuring TestBed setups that assert signal updates and verify OnPush change detection behavior. This approach ensures signal-based logic and rendering triggers function correctly without manual fixture handling.

Migrating Jasmine tests to Vitest requires adjusting angular.json and tsconfig.spec files for compatibility. You replace Jasmine spies with vi mocks while keeping TestBed-based setups intact to maintain reliable assertions during the transition.

Mocking HTTP interactions in Angular involves configuring TestBed with provideHttpClientTesting or HttpTestingController. You simulate backend responses and verify HTTP calls using vi spies to ensure your service logic handles requests and errors correctly.

Vitest supports component harnesses for Angular integration testing by combining TestBed setups with harness utilities. This allows you to interact with component elements programmatically, enabling robust assertions and repeatable test suites for complex UI behaviors.

You can use provideHttpClientTesting with inject() services in Angular v20 by configuring the TestBed environment accordingly. This setup intercepts HTTP requests from your services, allowing you to mock responses and validate service logic without real network dependencies.

Vitest snapshot tests for Angular OnPush components fail when change detection is not triggered properly before assertion. You must ensure the fixture detects changes or updates signals so the rendered output matches the expected snapshot state.