Testing Test Writing

Pest is a testing framework for Laravel that lets you write behavior-focused unit tests in the tests/Unit/ directory. Create descriptive test functions that verify specific business logic without testing implementation details, using assertions that check outcomes rather than internal state.

Feature tests in Pest verify complete user flows by simulating real interactions. Write tests for each critical path—like successful login, invalid credentials, and locked accounts—in tests/Feature/, mocking external dependencies so tests run fast and stay isolated.

Pest lets you mock external services and dependencies so your tests don't call real APIs or databases. Define mocks before your test runs, verify they were called correctly, and replace slow or unreliable external calls with controlled fake responses.

Pest supports datasets that let you run the same test with different inputs, eliminating duplicate test code. Define data parameters once and Pest executes the test for each scenario, making it easy to cover multiple cases like valid and invalid user inputs.

Tests that verify implementation details instead of behavior break when code is refactored, even if functionality stays the same. Behavior-driven testing focuses assertions on outcomes and user-visible results, so tests catch real bugs and stay stable through safe code changes.

Pest supports both unit tests in tests/Unit/ and integration feature tests in tests/Feature/. Use unit tests for isolated business logic and feature tests for complete workflows, building comprehensive coverage across critical paths and internal functions.