3 tips for stopping flaky tests

Key Takeaways

Flaky tests are the worst. Is your CI build failing again because of a test that only sometimes works? To maintain a high-quality codebase, you need reliable signals. Here are three quick tips [music] to stop flaky tests from wasting your time. Number one, isolate [music] your state. If your tests write to hard-coded file paths or shared databases, concurrent runs will collide. Use unique, temporary environments for every single run. Number two, take out your external dependencies. Disk I/O and network calls introduce randomness. Swap them out [music] with test fake to make your unit tests lightning fast and strictly deterministic. Number three, check your assumptions. Don't assume your test environment starts perfectly clean. Explicitly clear out existing data before executing. Stop ignoring red builds. Subscribe to Google for Developers for more testing tips.