Real-World Code Revealed What Unit Tests Couldn't: Bugs in Flagship Lint Rules

A ground-truth testing approach using real code patterns found three critical bugs in flagship lint rules that all passed traditional unit tests, exposing fundamental gaps in how code analysis tools are validated. The bugs ranged from false positives in React hook analysis to missed security vulnerabilities like NoSQL injection. This underscores why real-world testing is essential: lint rules validated only through synthetic test suites can harbor dangerous blind spots.