flaky-test-finderlisted

# Flaky test finder Flakiness is an empirical claim, and it is the one kind of test problem where reasoning from the source is actively misleading. A test that looks obviously order-dependent may be solid; a test that looks pure may fail one run in forty on a loaded machine. So this skill measures first and reads second. ## Procedure ### 1. Measure the rate `<skill-dir>` is the directory this SKILL.md was loaded from — the skill installs outside your project, so its script is named by full path, never relatively. ``` bash <skill-dir>/scripts/rerun.sh "pnpm vitest run path/to/file.test.ts" 30 ``` Runs the command N times, reports pass/fail per run, the observed failure rate, and a Wilson confidence interval for the true rate. **The interval is the point**: three failures in ten runs and three in a hundred are very different findings, and a bare percentage hides which one you have. If the failure rate is 0 over a decent number of runs, say so plainly — "not reproduced in N runs" is a real result. Do not go on to diagnose a flake you could not observe. ### 2. Split ordering from isolation The two commonest causes look identical from the failure message. Distinguish them: - Run the single test **alone**, many times. Failing alone means it is not order-dependent — look at timing, environment and external state. - Run the whole file, then the whole suite. If it only fails in the larger set, it is **shared state or ordering** — something before it leaves a mutation be