Overview
What this challenge is about.
Fork the repo (test mirror provided), set up Vitest with coverage and a CI workflow that fails under 75 percent on the targeted modules. Write characterization tests first (assert current behavior, including quirks) before adding new assertions. Find at least 4 bugs that show up only because the tests exist, file them as issues with a minimal failing test attached, and fix two of them in separate PRs. Deliver the PR series (link-only), a 2-page write-up covering tooling choices, bugs found, and the trade-off between coverage targets and meaningful tests, plus an updated CONTRIBUTING.md test section.
The Brief
What you'll do, and what you'll demonstrate.
Bring three critical modules of an untested OSS CLI from 8 percent to 75 percent meaningful test coverage and ship the work as reviewable PRs.
Earning criteria — what you'll demonstrate
- Distinguish characterization tests from specification tests in a legacy codebase
- Configure a CI coverage gate that does not become a rubber stamp
- Write a minimal failing test for a real bug before fixing it
- Trade off coverage targets against test maintenance cost
Program Fit
Where this fits in your program.
Sharpens the same skills your degree expects you to demonstrate.
Skills
Skills you'll demonstrate.
Each one shows up on your verified credential.
Careers
Roles this prepares you for.
Real titles. Real skill bridges. Pick the one closest to your trajectory.
Career mappings coming soon.