Fixing Flaky Tests

About

The Fixing Flaky Tests skill provides a systematic framework for identifying and eliminating non-deterministic test failures that disrupt CI/CD pipelines. It guides developers through a diagnostic flowchart to distinguish between shared state pollution, resource conflicts like port collisions, and race conditions. By offering concrete implementation patterns for database isolation, global variable resets, and worker-specific resource allocation, this skill helps ensure that test suites remain reliable and performant across Python, JavaScript, and E2E environments.

Key Features

• 62 GitHub stars
• Root cause diagnosis flowchart for shared state vs. resource conflicts
• Database isolation patterns including transaction rollbacks and savepoints
• Verification workflows for validating fixes through repeated parallel runs
• Resource conflict resolution for ports, file locks, and temp directories
• Strategies for managing global variables, singletons, and environment state

Use Cases

• Resolving port or file system collisions in multi-worker test environments
• Refactoring legacy test suites that suffer from global state pollution
• Stabilizing CI/CD pipelines where tests fail randomly during parallel execution