Flaky Tests

Flaky Tests

Flaky tests are automated checks that sometimes pass and sometimes fail even when the underlying code hasn't changed. Their outcomes depend on external or nondeterministic factors like timing, random data, network calls, or shared resources, rather than on a real bug in the software. Because of this unpredictability, flaky checks are unreliable and make it hard to trust the test suite. They matter because they create false alarms or mask real problems, which wastes developer time and slows down the development process. Teams address flakiness by isolating tests from external services, controlling timing and randomness, and ensuring proper setup and cleanup. Tools can help by rerunning failures, collecting logs, and highlighting unstable checks to diagnose root causes. In some cases a flaky test should be rewritten or adjusted so its behavior is deterministic under test conditions. Reducing flakiness restores confidence in automated testing, helps spot real regressions quickly, and keeps the development workflow efficient.