An Angular Testing Strategy That Supports Change
Combine focused unit tests, component behavior tests, integration coverage, and a small number of dependable end-to-end journeys.
A test suite should make change safer, not make every refactor feel dangerous. That happens when tests focus on observable behavior rather than private methods and incidental markup.
Use unit tests for pure transformations, validators, and business rules where inputs and outputs are clear. Test services at their important boundaries, including successful responses, failures, cancellation, and authorization behavior. Mock only what is necessary to isolate the responsibility being tested.
Component tests should interact through the interface. Enter values, activate controls, and check what a user can observe. Avoid asserting an exact internal component tree unless that structure is itself a requirement. Accessible roles and labels often make stronger selectors than CSS classes created for styling.
Integration tests are useful where routing, forms, data services, and permissions meet. Keep end-to-end coverage for a focused set of critical journeys such as signing in, completing a core workflow, and recovering from a failed request. Too many broad browser tests can become slow and fragile.
Run fast tests during development and the complete suite in continuous integration. Investigate flaky tests rather than rerunning them until they pass. A dependable suite builds confidence because failure means something, and success reflects behavior customers actually rely on.
