Cargo Cult Testing

ELI5 — The Vibe Check

Cargo cult testing is writing tests that look like real tests but don't actually test anything meaningful — checking that true equals true, mocking everything so the test only tests the mocks, or asserting that a function was called without checking if it did the right thing. The test suite is green, the coverage number is high, and the code is still broken.

Real Talk

Cargo cult testing is an anti-pattern where tests mimic the form of good tests without providing value. Common patterns: testing implementation details instead of behavior, over-mocking that makes tests tautological, snapshot tests that always get updated without review, and tests that pass regardless of code correctness. Effective tests verify behavior, catch regressions, and fail when code breaks.

When You'll Hear This

"These tests mock the entire database and then test... that the mock returns what it was told to return. Cargo cult testing." / "100% coverage means nothing if it's cargo cult testing."