Test Isolation
Designing tests so each runs independently, without relying on or interfering with any other test.
What is Test Isolation?
What is Test Isolation?
Test isolation is the principle that every test should stand on its own—it sets up its own state, makes no assumptions about what ran before it, and cleans up after itself so it leaves nothing behind for the next test. Isolated tests can run in any order and in parallel, which is essential for speed and reliability; coupled tests, by contrast, produce order-dependent flakiness that is miserable to debug. Playwright's per-test browser contexts and fixtures give recorded suites strong isolation by default.