reviewing-duplication

Duplicate code detection uses automated tools like jsinspect to scan your codebase and identify copy-pasted or near-duplicate blocks. The Skill runs duplication detection across your project, outputting file locations, line numbers, similarity percentages, and the actual duplicated code blocks for review.

Automated duplication detection with jsinspect is the fastest approach for large projects. It scans the entire codebase in one pass, finds duplicate blocks across multiple files, and provides similarity scores. Manual patterns are available for specific cases like config objects or validation logic when targeted search is needed.

The Skill uses jsinspect as the preferred detection engine with Lizard as a fallback option. Both are configured as dependencies. If neither is available, manual search patterns using Bash, Grep, and Glob can identify duplication, though they require more effort than automated tools.

After duplication detection identifies duplicate blocks, the Skill provides refactoring guidance to extract common logic into shared functions or utilities. This eliminates boilerplate and consolidates repeated patterns into reusable components.

Yes. The Skill detects duplication across multiple patterns: configuration objects, validation logic, data transformations, and function signatures. It handles both structural and behavioral duplication across JavaScript and TypeScript files.