Component Fix and Verify

Apply a diagnosed fix to a component and verify through scoped then broad checks with mandatory diff preview and atomic safety.

Scope Constraints

• Read access to source files, config files, and git state
• Write access to files listed in affectedFiles from the DiagnosisReport only
• Executes tsc, linter, and test runner commands — no other shell commands
• Does not modify files outside the diagnosed fix scope
• Revert restores original file contents only for files changed by this skill

Inputs

• DiagnosisReport (required): Path to .claude/qa-cache/artifacts/diag-*.json with rootCause and suggestedFix
• ComponentMap (required): Path to .claude/qa-cache/component-maps/{route-slug}.json
• FixResult from prior run (optional): If retrying after a FAIL verdict

Input Sanitization

• File paths from DiagnosisReport affectedFiles are validated against the ComponentMap's cachedFiles array. Reject any path not present in the ComponentMap or containing .., shell metacharacters, or absolute paths outside the project root.
• Shell commands are constructed from detected tool names (tsc, eslint, biome, vitest, jest, playwright) with file arguments. No user-provided strings are interpolated into commands.

Procedure

Copy this checklist and update as you complete each step:

Progress:
- [ ] Phase 1: Pre-flight (Steps 1-4)
- [ ] Phase 2: Preview (Steps 5-7)
- [ ] Phase 3: Apply (Steps 8-9)
- [ ] Phase 4: Scoped Verification (Steps 10-12)
- [ ] Phase 5: Broad Verification (Steps 13-15)
- [ ] Phase 6: Verdict (Step 16)

Note: If you've lost context of previous steps (e.g., after context compaction), check the progress checklist above. Resume from the last unchecked item. Re-read the verification-commands reference if needed.

Phase 1: Pre-flight

1. Run git status --short. If untracked or modified files exist outside the fix scope, warn: "Working tree has uncommitted changes in: [files]. These are unrelated to this fix." Pause for acknowledgment.
2. If no git repo, warn: "No git repository — revert will require manual undo." Pause.
3. Identify the files to change from the DiagnosisReport. Record them as affectedFiles.
4. Capture baseline state: run tsc --noEmit 2>&1 | tail -5 and record pre-existing error count. Note: "Baseline: N pre-existing type errors."

Phase 2: Preview

5. Generate the complete fix as a unified diff. Show it with a plain-language explanation:
   • What changes and why (1-2 sentences per file)
   • What this does NOT address — related issues the fix intentionally leaves untouched
   • Risk level: Low (style/typo), Medium (logic change), or High (architectural change, cross-file)
6. Pause: "Review the diff above. Apply this fix?"
7. Do NOT write any file until the user confirms.

Phase 3: Apply

8. Write the changes to disk. One fix at a time — never batch multiple independent fixes.
9. Record exactly what was written for revert reference.

Phase 4: Scoped Verification

10. Read references/verification-commands.md. Run scoped checks on affectedFiles only:
    • TypeScript: tsc --noEmit on affected files (see reference for project-specific variants)
    • Lint: detected linter on affected files (ESLint, Biome, or project lint script)
    • Tests: related tests only (vitest --related, jest --findRelatedTests, or directory-scoped)
11. If test runner is not detected or test command fails to start, report: "No test infrastructure detected. Verification limited to tsc + lint." Mark tests as SKIPPED.
12. If any scoped check fails, skip Phase 5. Go directly to Phase 6 with FAIL.

Phase 5: Broad Verification

13. Run full-project tsc --noEmit. Compare error count to Phase 1 baseline.
14. Run full test suite via the project's test script (npm test, pnpm test, etc.).
15. If broad checks introduce new failures beyond the Phase 1 baseline, go to Phase 6 with FAIL. If only pre-existing failures remain, go to Phase 6 with PARTIAL.

Phase 6: Verdict

Report one of three outcomes:

PASS — All scoped and broad checks green.

Fix verified: PASS
  tsc: 0 errors (was N baseline)
  lint: clean
  tests: M passed, 0 failed
  scope: [affectedFiles]

FAIL — Any check introduced new errors. Do NOT auto-revert. Show:

Fix verified: FAIL
  failed phase: [Scoped Verification | Broad Verification]
  failing check: [tsc | lint | tests]
  error: [first error message]
  files changed: [affectedFiles]

Options:
  1. Show full error output
  2. Revert this fix (restores original files)
  3. Keep changes and investigate

PARTIAL — Fix is clean but pre-existing failures exist in broad checks.

Fix verified: PARTIAL
  scoped checks: all passed
  broad checks: pre-existing failures detected (not caused by this fix)
  pre-existing: N type errors, M test failures (same as baseline)
  scope: [affectedFiles]

16. If user chooses revert on FAIL: restore the original file contents recorded in Phase 3, then confirm: "Reverted [N] files. Working tree matches pre-fix state."

Visual Triage (When Screenshots Provided)

If the DiagnosisReport includes before/after screenshots:

Tier 1 — Qualitative (always available): Examine both screenshots cross-referenced with the code changes. Report observations with mandatory disclaimers:

• "Visual analysis is qualitative, not pixel-accurate"
• "Sub-pixel differences require dedicated tooling"
• "Dynamic states (hover, animation) cannot be assessed from static screenshots"
• Never state "no visual differences" as a pass — say "no differences observed in static comparison"

Tier 2 — Automated (if tooling detected): Check for Playwright with toHaveScreenshot() or pixelmatch in dependencies. If found, scaffold the comparison command and run it. If not found, note: "Automated visual regression available with Playwright — see playwright.dev/docs/test-snapshots." Proceed with Tier 1 only.

Output Format

FixResult:
  version: "1.0"
  diagnosis_ref: "[DiagnosisReport ID]"
  affectedFiles: ["path/to/file.tsx"]
  diff: "[unified diff string]"
  verdict: "PASS | FAIL | PARTIAL"
  checks:
    tsc: { status: "pass|fail|skip", errors: 0, baseline: 0 }
    lint: { status: "pass|fail|skip", tool: "eslint|biome|none" }
    tests: { status: "pass|fail|skip", passed: 0, failed: 0, runner: "vitest|jest|none" }
  visual: { tier: "1|2|none", observations: "string" }
  notAddressed: ["related issue this fix does not cover"]
  reverted: false

Handoff

Pass the FixResult artifact path to qa-coordinator. The result contains verdict, affectedFiles, diff, and notAddressed fields consumed by regression-test-generator.

References