What problem does it solve?
Running full test suites for every small code change wastes hours of developer time, especially on large codebases with hundreds of tests. This skill eliminates that waste by only executing tests impacted by your recent code changes.
Core Features & Use Cases
- Incremental Test Impact Analysis (TIA): Runs only tests for changed files and their transitive callers, skipping unrelated tests entirely.
- Content-Hash Caching: Avoids re-running tests that already passed against unchanged file content, surviving branch switches and rebases.
- Flaky Test Detection: Automatically flags inconsistent test results and persists them to a quarantine list for follow-up, preventing silent failures from shipping to production.
- Automatic Full-Suite Overrides: Forces a full test run when configuration files, dependency manifests, or critical path code is changed, ensuring no regressions slip through.
Use case: For a team working on a mid-sized SaaS codebase, this skill cuts PR test feedback from 45 seconds to 2.3 seconds on average by skipping tests for unchanged code.
Quick Start
Use the smart-test-runner skill to run only the tests affected by the code changes you just made.
