repren

repren is a command-line refactoring tool that performs search-and-replace operations and file renaming at scale using regular expressions. It handles simultaneous renames (like swapping foo and bar without intermediate steps), case-preserving variants across lowerCamel, UpperCamel, and underscore conventions, and recursive directory operations with atomic file safety. The tool includes dry-run mode, automatic backups, and undo capabilities to prevent data loss. It has zero runtime dependencies and works on Python 3.10-3.14, making it lightweight and secure for developers, operations teams, and AI agents automating bulk refactors.

[{"step":"Identify the refactoring target. Determine whether you need to rename files, directories, or code elements (e.g., variables, functions, classes).","action":"Use grep or IDE search to find all occurrences of the old pattern. Example: `grep -r \"old_function\" .` to locate all references."},{"step":"Draft the regex patterns for the old and new names. Test them with `repren --dry-run` to preview changes.","action":"Run: `repren --dry-run --pattern 'old_pattern' --replacement 'new_pattern' --target 'files'`. Review the output for accuracy."},{"step":"Apply the refactoring in batches. Start with files, then directories, and finally code elements to minimize risk.","action":"Execute: `repren --pattern 'old_pattern' --replacement 'new_pattern' --target 'files'` followed by `repren --pattern 'old_pattern' --replacement 'new_pattern' --target 'code'`.","tip":"Use `--backup-dir` to create a backup of the original files before refactoring. Example: `--backup-dir ./backups/`"},{"step":"Verify the changes. Check for broken imports, syntax errors, or unintended modifications.","action":"Run tests: `pytest` or `npm test`. Use `git diff` to review changes. Fix any issues manually if needed."},{"step":"Integrate with Claude Code for advanced refactoring. Use the `repren` skill in combination with `Claude Code` to automate complex code transformations.","action":"Example: 'Use repren to rename all instances of `User` to `Account` in the `src/models/` directory, then use Claude Code to update the corresponding tests and documentation.'"}]