Parallel Test Execution | Bondar Academy

Lesson Summary

Playwright supports parallel test execution by default, allowing tests to run simultaneously across different spec files. This feature is configured in playwright-config.ts with the setting fullyParallel: true . Parallel Execution Configuration When fullyParallel is set to true , all tests across the framework are executed in parallel. Each parallel thread corresponds to a worker dispatched by Playwright. By default, if the UCI flag is passed, only a single worker is used. When running locally, the maximum number of workers is determined by the number of CPU cores available. Execution Scenarios If fullyParallel is set to false , tests within a single spec file run sequentially, but spec files can still execute in parallel. To disable parallel execution completely, set the maximum number of workers to one . Challenges with Parallel Execution While parallel execution can significantly speed up test runs, it may introduce challenges: Performance Limitations: The test environment may not handle multiple workers effectively, leading to flaky tests. Test Data Conflicts: Tests sharing the same data can interfere with each other, causing failures. To troubleshoot issues, first check the performance metrics of your environment. If performance is adequate, investigate the independence of your test data to ensure there are no dependencies that could lead to conflicts. In summary, while configuring parallel execution is straightforward, managing test data is crucial for successful automation.