Fixture

A known, reusable block of test data or environment state set up before a test runs, so every test starts from the same baseline.

📌 Example: A pre-built 'test user' account created fresh before each test.

🛠 In practice: Good fixtures are isolated and repeatable — a shared mutable fixture across tests is a common source of flakiness when one test's leftover state leaks into another.

• often caused by Flaky test