tests-purge-unneeded
Purge unneeded tests — deletion as discipline
Tests are not assets. Tests are liabilities that pay rent by catching real bugs. Volume is not a quality signal — coverage percentage is not a quality signal — only the counterfactual matters: if I delete this test, can a real bug now reach prod? If the answer is no, the test is dead weight, and dead weight slows CI, breeds noise, and trains reviewers to ignore failures.
Modern insight (2025): TDD pairs with purge discipline. The same rigor that earns RED before GREEN earns deletion before keep — a test that cannot describe the bug it would catch should not exist. Mutation testing exposes which tests are actually load-bearing; the rest are cargo cult.
See python for pytest examples (dynamic-language carve-out). See typescript for jest/vitest examples (static-language redundancy). See rust for cargo test examples (compile-time-guaranteed redundancy). See keep-vs-delete-table for the language-agnostic decision rubric.