remove-deadcode skill

Dead code removal via massively parallel deep agents. You are the ORCHESTRATOR — you scan, verify, batch, then delegate ALL removals to parallel agents.

• LSP is law. Verify with LspFindReferences(includeDeclaration=false) before ANY removal decision.
• Never remove entry points. src/index.ts, src/cli/index.ts, test files, config files, packages/ — off-limits.
• You do NOT remove code yourself. You scan, verify, batch, then fire deep agents. They do the work.

NEVER mark as dead:

• Symbols in src/index.ts or barrel index.ts re-exports
• Symbols referenced in test files (tests are valid consumers)
• Symbols with @public / @api JSDoc tags
• Hook factories (createXXXHook), tool factories (createXXXTool), agent definitions in agentSources
• Command templates, skill definitions, MCP configs
• Symbols in package.json exports

PHASE 1: SCAN — Find Dead Code Candidates

Run ALL of these in parallel:

TypeScript strict mode (your primary scanner — run this FIRST):

bunx tsc --noEmit --noUnusedLocals --noUnusedParameters 2>&1

This gives you the definitive list of unused locals, imports, parameters, and types with exact file:line locations.

Explore agents (fire ALL simultaneously as background):

task(subagent_type="explore", run_in_background=true, load_skills=[],
  description="Find orphaned files",
  prompt="Find files in src/ NOT imported by any other file. Check all import statements. EXCLUDE: index.ts, *.test.ts, entry points, .md, packages/. Return: file paths.")

task(subagent_type="explore", run_in_background=true, load_skills=[],
  description="Find unused exported symbols",
  prompt="Find exported functions/types/constants in src/ that are never imported by other files. Cross-reference: for each export, grep the symbol name across src/ — if it only appears in its own file, it's a candidate. EXCLUDE: src/index.ts exports, test files. Return: file path, line, symbol name, export type.")

Collect all results into a master candidate list.

PHASE 2: VERIFY — LSP Confirmation (Zero False Positives)

For EACH candidate from Phase 1:

LspFindReferences(filePath, line, character, includeDeclaration=false)
// 0 references → CONFIRMED dead
// 1+ references → NOT dead, drop from list

Also apply the false-positive-guards above. Produce a confirmed list:

| # | File | Symbol | Type | Action |
|---|------|--------|------|--------|
| 1 | src/foo.ts:42 | unusedFunc | function | REMOVE |
| 2 | src/bar.ts:10 | OldType | type | REMOVE |
| 3 | src/baz.ts:7 | ctx | parameter | PREFIX _ |

Action types:

• REMOVE — delete the symbol/import/file entirely
• PREFIX — unused function parameter required by signature → rename to paramName

If ZERO confirmed: report "No dead code found" and STOP.

PHASE 3: BATCH — Group by File for Conflict-Free Parallelism

Goal: maximize parallel agents with ZERO git conflicts.

1. Group confirmed dead code items by FILE PATH
2. All items in the SAME file go to the SAME batch (prevents two agents editing the same file)
3. If a dead FILE (entire file deletion) exists, it's its own batch
4. Target 5-15 batches. If fewer than 5 items total, use 1 batch per item.

Example batching:

Batch A: [src/hooks/foo/hook.ts — 3 unused imports]
Batch B: [src/features/bar/manager.ts — 2 unused constants, 1 dead function]
Batch C: [src/tools/baz/tool.ts — 1 unused param, src/tools/baz/types.ts — 1 unused type]
Batch D: [src/dead-file.ts — entire file deletion]

Files in the same directory CAN be batched together (they won't conflict as long as no two agents edit the same file). Maximize batch count for parallelism.

PHASE 4: EXECUTE — Fire Parallel Deep Agents

For EACH batch, fire a deep agent:

task(
  category="deep-low",
  load_skills=["typescript-programmer", "git-master"],
  run_in_background=true,
  description="Remove dead code batch N: [brief description]",
  prompt="[see template below]"
)

Every deep agent gets this prompt structure (fill in the specifics per batch):

## TASK: Remove dead code from [file list]

## DEAD CODE TO REMOVE

### [file path] line [N]
- Symbol: `[name]` — [type: unused import / unused constant / unused function / unused parameter / dead file]
- Action: [REMOVE entirely / REMOVE from import list / PREFIX with _]

### [file path] line [N]
- ...

## PROTOCOL

1. Read each file to understand exact syntax at the target lines
2. For each symbol, run LspFindReferences to RE-VERIFY it's still dead (another agent may have changed things)
3. Apply the change:
   - Unused import (only symbol in line): remove entire import line
   - Unused import (one of many): remove only that symbol from the import list
   - Unused constant/function/type: remove the declaration. Clean up trailing blank lines.
   - Unused parameter: prefix with `_` (do NOT remove — required by signature)
   - Dead file: delete with `rm`
4. After ALL edits in this batch, run: `bun run typecheck`
5. If typecheck fails: `git checkout -- [files]` and report failure
6. If typecheck passes: stage ONLY your files and commit:
   `git add [your-specific-files] && git commit -m "refactor: remove dead code from [brief file list]"`
7. Report what you removed and the commit has

Fire ALL batches simultaneously. Wait for all to complete.

PHASE 5: FINAL VERIFICATION

After ALL agents complete:

bun run typecheck   # must pass
bun test            # note any NEW failures vs pre-existing
bun run build       # must pass

Produce summary:

## Dead Code Removal Complete

### Removed
| # | Symbol | File | Type | Commit | Agent |
|---|--------|------|------|--------|-------|
| 1 | unusedFunc | src/foo.ts | function | abc1234 | Batch A |

### Skipped (agent reported failure)
| # | Symbol | File | Reason |
|---|--------|------|--------|

### Verification
- Typecheck: PASS/FAIL
- Tests: X passing, Y failing (Z pre-existing)
- Build: PASS/FAIL
- Total removed: N symbols across M files
- Total commits: K atomic commits
- Parallel agents used: P

SCOPE CONTROL

If $ARGUMENTS is provided, narrow the scan:

• File path → only that file
• Directory → only that directory
• Symbol name → only that symbol
• all or empty → full project scan (default)

ABORT CONDITIONS

STOP and report if:

• More than 50 candidates found (ask user to narrow scope or confirm proceeding)
• Build breaks and cannot be fixed by reverting