Refactor

/refactor — Safe Multi-File Refactoring

Orientation

Use /refactor when you need to:

• Rename a symbol, file, or module across the codebase
• Extract a function, component, hook, class, or module from existing code
• Inline a function or module back into its callers
• Move a file or set of files to a new location
• Split a large file into smaller pieces
• Merge related files into one
• Change a function signature and update all call sites

Don't use when: debugging a specific bug (use /systematic-debugging); adding new features (use /marshal or /scaffold); deleting dead code (use /marshal for a targeted cleanup).

Boundary with /organize: /refactor changes code structure within files (extract, inline, split, merge, rename) and moves files as part of those operations. Repository-wide file/directory placement, naming sweeps, and where-does-this-belong decisions are /organize.

Behavior does not change. Tests pass before and after, no new type errors — the refactoring is correct.

Commands

Protocol

Phase 1: BASELINE

Run typecheck (via node scripts/run-with-timeout.js 300 npm run typecheck) and tests. Record error/failure counts — pre-existing issues are not your responsibility, but you must not add to them. Warn if there are uncommitted changes in files you plan to modify.

Baseline established:
  Typecheck: {pass | N errors (pre-existing)}
  Tests: {pass | N failures (pre-existing) | no test suite found}
  Git: {clean | M files with uncommitted changes}

Phase 2: PLAN

Analyze the refactoring target and produce a concrete plan.

1. Identify scope: Search the codebase for every reference to the target. Use grep/search for:

   • Import statements referencing the target
   • Usage sites (function calls, type references, component usage)
   • Re-exports from index files
   • Test files that reference the target
   • Documentation or comments mentioning the target
   • Config files (e.g., route definitions, dependency injection)

2. Classify the refactoring type and apply type-specific analysis:

   Rename (symbol): all imports + usage sites + string references + dynamic access patterns (obj[key])

   Rename (file/module): all import paths + path aliases + dynamic imports + index re-exports

   Extract (function/component/module): code to extract, enclosing-scope dependencies, return values back to caller, destination file, interface design

   Move (file): every import of old path → compute new relative paths, check alias boundary changes, barrel updates

   Split (file): logical groupings, internal cross-references, which group keeps the original path, new files per group, index if needed

   Merge (files): duplicates/conflicts, import consolidation, merged file organization

3. Produce the plan — list every file that will change and what changes:

Refactoring Plan: {type} — {description}

Files to modify:
  1. {file}: {what changes and why}
  2. {file}: {what changes and why}
  ...

Files to create:
  - {file}: {extracted from where, contains what}

Files to delete:
  - {file}: {contents moved to where}

Risk assessment:
  - {any concerns: dynamic references, string-based lookups, config files}

4. If --dry-run was specified, output the plan and stop.

Phase 3: EXECUTE

Apply changes in this order to minimize intermediate breakage:

1. Create new files first (exports only, not yet imported)
2. Update importers to point to new locations/names
3. Update the source file (remove extracted code, rename, etc.)
4. Delete old files last (only after all importers are updated)
5. Update index/barrel files

Read each file before editing. Make the minimal change needed — do not reformat unrelated code.

Phase 4: VERIFY

Run typecheck and tests from Phase 1. Compare against baseline — any NEW errors or failures? Search for import paths referencing old/deleted files.

Verification: PASS
  Typecheck: {pass | same N pre-existing errors}
  Tests: {pass | same N pre-existing failures}
  No new broken imports detected.

Phase 5: FIX (if verification fails)

Two attempts: read errors, identify root cause (missed import update, missing re-export, type mismatch), fix, re-run verification. After 2 failed attempts: REVERT.

Phase 6: REVERT (if fixes fail)

1. Use git checkout -- [files] to restore every modified file
2. Remove any newly created files
3. Verify the revert: typecheck should match baseline exactly
4. Report what went wrong

REVERTED — Refactoring could not be completed cleanly.

Root cause: {why the refactoring failed}
Errors encountered:
  - {error 1}
  - {error 2}

Suggestion: {what the user might do differently}

Fringe Cases

• No test baseline: no test suite found in Phase 1 — output: "No tests found. Refactor proceeds without a safety net — abort or continue? Recommend running /test-gen first." Wait for user confirmation before continuing.
• Baseline typecheck fails: typecheck errors exist before any refactor changes — output: "Baseline typecheck failed. Fix existing type errors before refactoring to establish a clean baseline." Do not proceed.
• Build fails after refactor commit: Phase 4 build regression detected — revert the commit with git revert HEAD --no-edit, then report which verification step introduced the regression and what the failing error is.
• Circular dependency detected: import cycle surfaces during scope analysis — treat as a blocker; output: "Circular dependency detected in [file]. Resolve the cycle before proceeding." Do not modify that file without explicit user decision.
• Target file exceeds 500 lines: output: "Warning: [file] is [N] lines. Refactoring may split this file into multiple pieces. Confirm scope before proceeding." Show the proposed split in the plan and wait for user approval.

Quality Gates

• Zero new type errors — zero NEW ones, not just fewer.
• Zero new test failures — baseline failures accepted, new failures are not.
• All imports resolve — no dangling references to old paths or removed exports.
• Behavior unchanged — adding logic or changing return values is scope creep; stop and do it separately.
• Minimal diff — no reformatting, unrelated cleanups, or whitespace changes in untouched files.
• Plan matches execution — every planned file modified, no unplanned files touched.

Exit Protocol

Report the result:

=== Refactor Report ===

Type: {rename | extract | inline | move | split | merge}
Target: {what was refactored}

Changes:
  Modified: {N} files
  Created: {N} files
  Deleted: {N} files

Verification:
  Typecheck: {pass | same baseline errors}
  Tests: {pass | same baseline failures | no test suite}

Key decisions:
- {any non-obvious choices made during execution}

---HANDOFF---
- Refactored {target}: {what changed}
- {N} files modified, {N} created, {N} deleted
- Typecheck and tests pass (no regressions)
- {any follow-up suggestions}
- Reversibility: green -- single atomic commit, revert with git revert HEAD
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