Community Knip Dead Code Detection Best Practices

Comprehensive guide for detecting and removing dead code in JavaScript and TypeScript projects using Knip. Contains 43 rules across 8 categories, prioritized by impact to guide configuration, CI integration, and cleanup workflows.

When to Apply

Reference these guidelines when:

• Configuring Knip for a new project or monorepo
• Investigating false positives or false negatives
• Setting up CI pipelines to prevent dead code regressions
• Using auto-fix to clean up unused code
• Optimizing Knip performance for large codebases

Rule Categories by Priority

| Priority | Category | Impact | Prefix | |----------|----------|--------|--------| | 1 | Configuration Foundations | CRITICAL | config- | | 2 | Entry Point Strategy | CRITICAL | entry- | | 3 | Workspace & Monorepo | HIGH | workspace- | | 4 | Dependency Analysis | HIGH | deps- | | 5 | Export Detection | MEDIUM-HIGH | exports- | | 6 | CI Integration | MEDIUM | ci- | | 7 | Auto-Fix Workflow | MEDIUM | fix- | | 8 | Performance Optimization | LOW-MEDIUM | perf- |

Quick Reference

1. Configuration Foundations (CRITICAL)

• config-avoid-broad-ignore - Avoid broad ignore patterns
• config-configure-path-aliases - Configure path aliases in Knip
• config-enable-plugins-explicitly - Enable framework plugins explicitly
• config-run-without-config - Run without config first for baseline
• config-separate-entry-project - Separate entry files from project files
• config-use-json-schema - Use JSON schema for configuration validation
• config-use-negation-patterns - Use negation patterns for exclusions
• config-use-production-mode - Use production mode for shipping code analysis

2. Entry Point Strategy (CRITICAL)

• entry-add-dynamic-imports - Add dynamic import targets as entry points
• entry-exclude-test-files - Exclude test files from production entries
• entry-include-all-entry-points - Include all application entry points
• entry-include-bin-scripts - Include binary scripts as entry points
• entry-use-compilers - Use compilers for non-standard file types
• entry-use-plugin-entries - Use plugin entry points for frameworks
• entry-verify-with-debug - Verify entry points with debug mode

3. Workspace & Monorepo (HIGH)

• workspace-configure-root-workspace - Configure root workspace explicitly
• workspace-ignore-specific - Ignore specific workspaces when needed
• workspace-isolate-for-strict - Isolate workspaces for strict dependency checking
• workspace-list-cross-deps - List cross-workspace dependencies explicitly
• workspace-per-workspace-plugins - Configure plugins per workspace
• workspace-use-workspace-globs - Use workspace globs for consistent configuration

4. Dependency Analysis (HIGH)

• deps-add-unlisted-deps - Add unlisted dependencies to package.json
• deps-avoid-transitive-reliance - Avoid relying on transitive dependencies
• deps-configure-plugin-deps - Configure plugins for tool-specific dependencies
• deps-fix-files-first - Fix unused files before dependencies
• deps-ignore-conditional-deps - Ignore conditionally loaded dependencies
• deps-remove-obsolete-types - Remove obsolete type definition packages

5. Export Detection (MEDIUM-HIGH)

• exports-check-class-members - Check class members for unused code
• exports-enable-entry-exports - Enable entry export checking for private packages
• exports-handle-reexports - Handle re-exports in barrel files
• exports-ignore-same-file - Ignore exports used in same file
• exports-tag-public-api - Tag public API exports with JSDoc
• exports-trace-usage - Trace export usage before removal
• exports-use-include-libs - Use include libs for type-based consumption

6. CI Integration (MEDIUM)

• ci-add-to-pipeline - Add Knip to CI pipeline
• ci-separate-production-check - Separate production and default mode checks
• ci-use-cache - Enable cache for faster CI runs
• ci-use-max-issues - Use max issues for gradual adoption
• ci-use-reporters - Use appropriate reporters for CI output
• ci-watch-mode-local - Use watch mode for local development

7. Auto-Fix Workflow (MEDIUM)

• fix-allow-remove-files - Explicitly allow file removal
• fix-format-after-fix - Format code after auto-fix
• fix-review-before-commit - Review auto-fix changes before commit
• fix-update-deps-after - Update package manager after dependency fix
• fix-use-fix-type - Use fix type for targeted cleanup

8. Performance Optimization (LOW-MEDIUM)

• perf-filter-issue-types - Filter issue types for focused analysis
• perf-limit-output - Limit output for large codebases
• perf-profile-performance - Profile performance for slow analysis
• perf-use-bun-runtime - Use Bun runtime for faster analysis
• perf-use-cache-flag - Enable cache for repeated analysis
• perf-use-workspace-filter - Filter workspaces for faster monorepo analysis

How to Use

Read individual reference files for detailed explanations and code examples:

• Section definitions - Category structure and impact levels
• Rule template - Template for adding new rules

Reference Files

| File | Description | |------|-------------| | references/_sections.md | Category definitions and ordering | | assets/templates/_template.md | Template for new rules | | metadata.json | Version and reference information |