Configuration files require careful validation to ensure they work as intended and don’t introduce unintended side effects. This includes verifying ignore patterns don’t create parent-child conflicts, understanding rule severity implications, and confirming dependency changes are expected.

For ignore patterns, ensure re-inclusion rules don’t conflict with parent directory exclusions:

# Bad: Can't re-include files in ignored parent directories
/tests/format/**/*.*
!/tests/format/**/format.test.js

# Good: Re-include parent directories first
/tests/format/**/*.*
!/tests/format/**/*.*/
!/tests/format/**/format.test.js

For rule configurations, understand the difference between “error” and “warn” severity levels and use appropriate tooling flags like --max-warnings=0 to enforce standards consistently.

For dependency changes, use tools like yarn why to understand why specific versions exist and yarn-deduplicate to clean up duplicate dependencies before merging.

Always test configuration changes locally and verify they produce the expected behavior across different scenarios.