Feature tests verify a user-visible workflow across Laravel's request handling and persistence layers. They complement unit tests that isolate a small calculation or domain rule.
Test observable behavior
Send a request, assert the response, and verify the intended database state. Use factories to describe the records a scenario requires. Keep each test focused enough that its name and assertions explain the behavior.
Include negative cases
Test missing fields, malformed values, unauthenticated access, denied policies, and repeated submissions. For a transaction, verify that rejection leaves related data unchanged. These tests protect boundaries that a happy-path-only suite misses.
Isolate external services
Fake mail, queues, or storage when the test concerns application decisions rather than the external provider. Keep secrets and production services out of test setup. Run focused tests while iterating and the relevant suite before releasing.
A useful test suite is readable documentation: it shows what the application promises and which edge cases matter.