deja-code

You can detect duplicate code patterns in real-time by implementing custom ESLint rules that flag matching logic during development, immediately surfacing existing shared utilities and their file paths to prevent codebase duplication.

To create a custom ESLint rule for a multi-file JavaScript project, implement the rule named deja-code-<name>, wire it into your local lint configuration, and update the utility catalog with the new rule entry to enforce consistent shared helper usage.

Yes, this pattern detection approach works with both JavaScript and TypeScript codebases, specifically targeting multi-file projects that reuse utilities to ensure consistent usage and reduce cognitive load across the codebase.

The best way to surface existing utilities is through real-time ESLint errors that provide clear guidance to the file path of the existing implementation, immediately alerting developers when they draft code that duplicates shared logic.

ESLint errors provide real-time code analysis that catches duplicated logic as you type, directly pointing to existing implementations, whereas manual code reviews occur later and often miss subtle shared utility matches across multiple files.

Before wiring custom lint rules into your local config, you need a multi-file JavaScript or TypeScript project with shared utilities, an existing ESLint setup, and a catalog to update with the new rule definitions for accurate pattern detection.