Dead Code

Dead Code

Scan the codebase for unused code, orphaned files, and stale dependencies. Outputs a prioritized cleanup list.

Process

1. Determine scope:

   • If $ARGUMENTS specifies a package or directory, scope the scan there.
   • Otherwise, scan the entire project (or all packages in a monorepo).
   • Read CLAUDE.md for project conventions.

2. Scan for unused exports:

   • For each file, identify exported functions, types, constants, and components.
   • Search the rest of the codebase for imports of each export.
   • Flag exports that are never imported anywhere (excluding entry points, API routes, and config files that are consumed externally).

3. Scan for orphaned files:

   • Identify files that are not imported by any other file.
   • Exclude entry points (pages, routes, API handlers, config files, scripts referenced in package.json).
   • Exclude test files, config files, and other files that are consumed by tools rather than imports.

4. Scan for stale dependencies:

   • Read package.json dependencies and devDependencies.
   • Search the codebase for actual usage of each dependency (imports, requires, CLI usage in scripts).
   • Flag dependencies that appear unused.
   • Note: some dependencies are used implicitly (PostCSS plugins, Babel presets, ESLint configs) — do not flag these.

5. Scan for dead code patterns:

   • Unreachable code after return/throw statements.
   • Commented-out code blocks (more than 3 lines).
   • Functions defined but never called (within a single file, non-exported).
   • Unused variables and parameters (if not caught by linting).
   • Feature flags or environment checks for conditions that are always true/false.

6. Cross-reference with git:

   • For flagged items, check git log to see when they were last meaningfully modified.
   • Items untouched for 6+ months get higher priority.

7. Verify findings (false-positive filter):

   • Before finalizing, re-read the actual source code for every flagged item. For each one, confirm:
     • The export/function is genuinely unused — re-check imports, re-exports through barrel files, and dynamic usage (import(), require(), string-based references).
     • The "orphaned" file isn't consumed by a tool, framework convention, or config (e.g., Next.js pages, migration files, seed scripts).
     • The "stale" dependency isn't used implicitly (PostCSS plugins, Babel presets, peer dependencies, CLI tools in npm scripts).
     • Commented-out code isn't an intentional reference or example kept for documentation purposes.
   • Drop any finding you cannot re-confirm with a second read. If uncertain, move it to "Needs Investigation" rather than "Safe to Remove."

Output Format

Unused Exports (high confidence)

Orphaned Files

• path/to/orphan.ts — not imported anywhere, last modified X ago

Stale Dependencies

• some-package — no imports found in codebase
• another-package — only used in deleted file

Dead Code Patterns

• file.ts:42 — unreachable code after return
• file.ts:100-115 — commented-out code block

Safe to Remove (recommended)

Prioritized list of items safe to remove, grouped by package/directory.

Needs Investigation

Items that might be unused but have ambiguous usage patterns (dynamic imports, reflection, external consumption).

Follow-Through

After presenting findings, write actionable cleanup items to tasks/todo.md. If a finding is only a non-blocking future validation or condition-gated cleanup record, write it to tasks/record-todo.md instead with source, condition, non-blocking reason, evidence, and promotion rule:

1. Read tasks/todo.md if it exists — append to the end under a ## Dead Code Cleanup heading (create the file if it doesn't exist).
2. Add one checkbox item per "Safe to Remove" finding, grouped by package/directory:

   ## Dead Code Cleanup
   > Generated by `/dead-code` on [date]
   - [ ] Remove unused export `unusedHelper` from `path/to/file.ts`
   - [ ] Delete orphaned file `path/to/orphan.ts`
   - [ ] Remove stale dependency `some-package`
   

3. Do not add "Needs Investigation" items — only "Safe to Remove" items belong in todo.
4. If tasks/todo.md already has a ## Dead Code Cleanup section, replace it with the fresh scan results.
5. Tell the user how many items were added and suggest /run to execute the cleanup.

Constraints

• Use subagents to parallelize scanning across packages in a monorepo.
• Never automatically delete anything — only report findings and write todo items.
• Be conservative with false positives — it's better to miss a dead export than to flag a used one.
• Exclude files matching common non-import patterns: .config., .d.ts, migration files, seed files, scripts in bin/.
• If the codebase has a barrel file pattern (index.ts re-exports), trace through barrel files.

Alignment Page

When this skill produces durable deliverables (research, specs, plans, reports, prototypes, or any document output), build a full-depth HTML alignment page at alignment/dead-code-{topic}.html. Use a normalized topic slug derived from the app, feature, research subject, report subject, or output filename.

Full content requirement. The alignment page must contain the complete content of every proposed markdown deliverable -- every section, every finding, every detail, every list item. It is a thorough interactive review document, not a summary. Render the full deliverable content in clean, readable HTML with appropriate hierarchy, styling, and navigation. If the skill writes multiple scoped deliverables in one run, build one alignment page that contains all deliverables with anchor-linked navigation. Durable tracker artifacts, such as research/assumption-tracker.md, remain canonical markdown outputs but must also be fully rendered into the alignment page before approval.

Dark-mode styling. Use a dark color scheme by default. Base CSS variables: --bg: #0d1117; --surface: #161b22; --border: #30363d; --text: #c9d1d9; --text-muted: #8b949e; --accent: #58a6ff; --green: #3fb950; --red: #f85149; --orange: #d29922; --purple: #bc8cff;. Apply background: var(--bg); color: var(--text); on body. Use --surface for cards, nav, and table headers. Use --border for all borders. Use --purple for question blocks and gate headings. Use --accent for links and section headings. Keep headings color: #fff or var(--accent) for hierarchy. Question block backgrounds should use #1c2333.

Alignment gates. Treat gates as explicit review sections inside the HTML page. A gate blocks finalization until its required inline questions are answered and compiled into YAML. Include every gate that applies to the skill output, and include these gate types whenever relevant: evidence coverage, assumptions/confidence, scope/non-goals, candidate/verdict decisions, artifact destination, proposed file changes, coverage checkpoint, and post-approval route.

Report-only research gates. For report-only or pre-approval research skills, the alignment page must explicitly contain evidence coverage, assumptions/confidence, recommended path, proposed file changes, and approval gates before any canonical research, spec, or task file is created or updated.

Required inline questions. Each gate must contain at least one required inline question placed directly under the content it governs, inside a visually distinct question block. Each question must use radio-button inputs and include two standing options after the skill-generated choices: "Other / None of the above" backed by a multi-line text box for free-form input, and "Need clarification" backed by an optional notes box where the user can explain what is unclear. When any radio option other than "Other" or "Need clarification" is selected, show an optional "Additional notes" text box beneath it so the user can qualify their choice. Generate questions based on what genuinely needs user input -- do not add filler questions. Do not create a separate bottom "Decisions & Clarifications" section.

Gate YAML contract. At the bottom of the page, include a "Compile Answers" button that aggregates answers from all inline gate questions throughout the page, including free-text notes. The button remains disabled until every required question has a selection, shows a count of remaining unanswered questions, and scrolls to the first unanswered question if clicked early. When every question is answered, generate a structured YAML block with one item per gate answer using this stable shape: section, gate_type, status (answered, other, or needs-clarification), answer, optional notes, and optional target_artifact or target_path when the gate controls file output. After successful compilation, automatically attempt to copy the YAML to the clipboard with the Clipboard API, display copy status, and display the YAML in a read-only textarea with an explicit "Copy YAML" button. The copy button must retry clipboard copy when supported and fall back to selecting the textarea contents when clipboard access is unavailable or blocked.

Pre-approval stop. Before user approval, the next action is review of the HTML alignment page, not downstream routing. Ask the user to review the page and provide the compiled YAML answers. Do not include Recommended next skill, Recommended next command, or downstream routing language until after compiled YAML has been provided and the approved artifacts have been written or updated.

Diff highlighting on updates. When the agent updates an existing alignment page after receiving compiled answers, highlight what changed since the previous version. The agent chooses inline annotation or side-by-side layout per situation.

Archiving. Before replacing an existing alignment page, archive it to docs/history/archive/YYYY-MM-DD/HHMMSS/alignment/dead-code-{topic}.html.

Browser open. Attempt to open the resulting HTML page in the browser and report whether the open succeeded or was blocked. A blocked browser-open attempt does not make the skill fail when the files were written correctly.

Default Shipping Contract

• Default next-step routing: when reporting completion, include either Recommended next skill: <command> or the two-line pair **Next work:** <specific task or "none"> and **Recommended next command:** <one command or route> so the next operator has a concrete handoff.
• If this skill creates or modifies tracked repository files, finish by committing and pushing all intended changes to the repository primary branch (main when present, otherwise master) before stopping, even if the user did not explicitly ask for commit/push.
• Do not leave tracked changes or unpushed commits behind. If unrelated tracked work is already present, either include it in sensible commits too or stop and explain the blocker.
• This contract does not override stricter safety rules about secrets, destructive history changes, release publication/tag confirmation, or production deploy confirmation.