Bazel Test Hygiene

The Three Rules

1. Always disable caching

bazel test //... --nocache_test_results

Why: Bazel's action cache can serve stale test binaries even after you edit source files. Without --nocache_test_results, you may be running the OLD binary and seeing OLD results. This is not hypothetical — it has caused real false-positive/false-negative confusion in this repo.

Always include --nocache_test_results. No exceptions.

2. Keep it simple — no filter flags

Do NOT use --test_arg='-f' or similar filter flags to run individual test cases.

Why: KJ test's -f flag silently passes when zero tests match. If you typo the filter or the test name changes, bazel reports "PASSED" with zero tests actually run. This gives completely false confidence.