/refactor-clean

description: Safely identify and remove dead code with verification after each change.

Refactor Clean

Safely identify and remove dead code with test verification at every step.

Step 1: Detect Dead Code

Run analysis tools based on project type:

| Tool | What It Finds | Command | |------|--------------|---------| | knip | Unused exports, files, dependencies | `npx knip` | | depcheck | Unused npm dependencies | `npx depcheck` | | ts-prune | Unused TypeScript exports | `npx ts-prune` | | vulture | Unused Python code | `vulture src/` | | deadcode | Unused Go code | `deadcode ./...` | | cargo-udeps | Unused Rust dependencies | `cargo +nightly udeps` |

If no tool is available, use Grep to find exports with zero imports:

# Find exports, then check if they're imported anywhere

Step 2: Categorize Findings

Sort findings into safety tiers:

| Tier | Examples | Action | |------|----------|--------| | **SAFE** | Unused utilities, test helpers, internal functions | Delete with confidence | | **CAUTION** | Components, API routes, middleware | Verify no dynamic imports or external consumers | | **DANGER** | Config files, entry points, type definitions | Investigate before touching |

Step 3: Safe Deletion Loop

For each SAFE item:

1. **Run full test suite** — Establish baseline (all green) 2. **Delete the dead code** — Use Edit tool for surgical removal 3. **Re-run test suite** — Verify nothing broke 4. **If tests fail** — Immediately revert with `git checkout -- <file>` and skip this item 5. **If tests pass** — Move to next item

Step 4: Handle CAUTION Items

Before deleting CAUTION items:

• Search for dynamic imports: `import()`, `require()`, `__import__`
• Search for string references: route names, component names in configs
• Check if exported from a public package API
• Verify no external consumers (check dependents if published)

Step 5: Consolidate Duplicates

After removing dead code, look for:

• Near-duplicate functions (>80% similar) — merge into one
• Redundant type definitions — consolidate
• Wrapper functions that add no value — inline them
• Re-exports that serve no purpose — remove indirection

Step 6: Summary

Report results:

Dead Code Cleanup
──────────────────────────────
Deleted:   12 unused functions
           3 unused files
           5 unused dependencies
Skipped:   2 items (tests failed)
Saved:     ~450 lines removed
──────────────────────────────
All tests passing PASS:

Rules

• **Never delete without running tests first**
• **One deletion at a time** — Atomic changes make rollback easy
• **Skip if uncertain** — Better to keep dead code than break production
• **Don't refactor while cleaning** — Separate concerns (clean first, refactor later)