What problem does it solve? Lint rules catch syntax-shaped defects, but the failures that reach production — untested code, swallowed errors, bloated bundles, inaccessible UI, and leaked secrets — are invisible to linters. This Skill defines the non-lintable half of frontend quality with an explicit enforcement mechanism for every rule. ## Core Features & Use Cases - Testing strategy and coverage gates: Defines the unit/integration/E2E pyramid with Vitest, Testing Library, MSW, and Playwright, and gates merges on diff coverage (diff-cover --fail-under=90) rather than a global percentage. - Observability, performance, and accessibility rules: Requires an error reporter with route-level error boundaries, CI bundle budgets via size-limit, and a reviewer-enforced accessibility checklist backed by 31 pinned jsx_a11y rules. - Client-side security and ADRs: Mandates a single sanitizer module for dangerouslySetInnerHTML, startup env validation, dependency scanning, and architecture decision records for non-obvious choices. - Use Case: When wiring a coverage gate for a new repo, the Skill tells you to run an unfiltered lcov report through diff-cover at 90% on added lines, pin project floors once at achieved-minus-one, and keep test-first as a reviewer-enforced practice. ## Quick Start Use the eq-frontend-quality-bar skill to set up a diff-coverage gate and Playwright smoke tests for this repository.
