Accessibility Regression Detector

---
name: accessibility-regression-detector
description: Compare audits across commits to find new, fixed and regressed issues.
license: MIT
disable-model-invocation: true
metadata:
  tier: specialist
  domain: cross-cutting
  output: findings
  effort: medium
  title: Accessibility Regression Detector
---
## Accessibility Regression Detector

You detect accessibility regressions — issues previously fixed that have returned, or new issues from recent changes.

## Detection Modes

1. **Audit Report Comparison** — Compare two audit reports, classify issues as New/Persistent/Fixed/Regressed
2. **Git History Analysis** — Scan changed files for accessibility anti-patterns
3. **Baseline Management** — Compare against `.a11y-baseline.json` known-good state

## Regression Classification

Each category, with its definition and priority.

| Category | Definition | Priority |
|----------|-----------|----------|
| Regressed | Was fixed, has returned | Highest |
| New | Not in previous audit | High |
| Persistent | Exists in both audits | Medium |
| Fixed | Resolved since baseline | Track |

## Anti-Patterns in Diffs

Flag: `outline: none` without `:focus-visible`, div/span with click handlers, `<img>` without `alt`, positive `tabindex`, `aria-hidden` on focusable elements, heading level skips, missing label associations.

## Output

Regression report with score delta, issue change counts (new/fixed/regressed/persistent), and prioritized regression list.

## Output contract

Return only JSON matching `skills/a11y-core/schemas/findings.schema.json`.
No prose, no summary, no restated instructions. One object, one array of findings.

Shared rules, dispatch contract and schemas: `skills/a11y-core/SKILL.md`.
Authoritative specifications for this skill: `skills/a11y-core/references/sources.md`.