qa-differ

QA Differ — Drift Detection

Compare the project's current state against previously generated QA artifacts to detect what needs updating.

When This Skill Is Invoked

Called by /qa:audit (read-only report) and /qa:sync (to determine what to regenerate).

Workflow

Phase 1: Gather Current State

1. Run detect-stack.js → get current stack info
2. Run analyze-tests.js → get current test analysis
3. Read .claude/qa-config.json → get saved state from last init/sync

Phase 2: Compare

For each dimension, compare current vs. saved:

Stack drift:

• Language changed? (rare but possible)
• Framework changed or added?
• Test runner changed (e.g., Jest → Vitest)?
• New coverage tool?
• New CI setup?

Module drift:

• New source directories/modules added?
• Modules removed?
• Significant new files (new API routes, new components)?

Test drift:

• New test files added outside QA plugin guidance?
• Test conventions changed?
• New testing patterns detected?

Phase 3: Classify Artifacts

For each generated artifact, assign a status:

• CURRENT — No relevant drift detected. Artifact is still accurate.
• OUTDATED — Minor drift. Artifact mostly correct but missing new modules or patterns.
• STALE — Major drift. Stack or framework changed. Artifact needs full regeneration.
• MISSING — Expected artifact doesn't exist (e.g., new module type needs new guidance).

Phase 4: Produce Report

## Drift Report

### Stack Changes
- testRunner: jest → vitest (CHANGED)
- framework: react → next (CHANGED)

### Artifact Status
| Artifact | Status | Reason |
|----------|--------|--------|
| qa-test-writer/SKILL.md | STALE | Test runner changed from jest to vitest |
| qa-use-case-identifier/SKILL.md | OUTDATED | 3 new API routes not covered |
| qa-coverage-analyzer/SKILL.md | CURRENT | — |
| qa-test-reviewer/SKILL.md | CURRENT | — |
| test-runner/AGENT.md | STALE | Test runner changed |
| test/COMMAND.md | STALE | Test command changed |

### Recommended Actions
1. Run /qa:sync to regenerate STALE artifacts
2. Run /qa:sync to extend OUTDATED artifacts

Critical Rules

1. Read actual files — Compare against real .claude/qa-config.json, not assumptions.
2. Be conservative — If unsure whether something drifted, mark as OUTDATED (not STALE).
3. Stay read-only — This skill produces a report. It does NOT modify files. /qa:sync acts on this report.