@ariada-org/evidence-emitter

Pure-function emitters that turn a normalized list of accessibility violations into machine-readable compliance evidence — VPAT 2.5, EN 301 549 §11, Swedish DOS-lagen.

Quick-start

npm install @ariada-org/evidence-emitter

import {
  emitVpat,
  emitEn301549,
  emitDosLagen,
} from "@ariada-org/evidence-emitter";
import type { Violation, ReportMeta } from "@ariada-org/evidence-emitter";

const violations: Violation[] = [
  /* axe-core results normalized */
];
const meta: ReportMeta = {
  productName: "Example Web App",
  productVersion: "2.5.0",
  evaluator: "Audit Team",
  evaluationDate: "2026-05-16",
  scope: "https://example.com/checkout",
};

const vpat = emitVpat(violations, meta);
const en301549 = emitEn301549(violations, meta);

Node ≥ 22. No runtime dependencies, no network, no DOM mutation.

What this package does

Three deterministic functions take a Violation[] plus ReportMeta and return JSON-serialisable report objects in the three formats most often demanded by EU + US procurement, regulator notifications, and .well-known/ publication:

• VPAT 2.5 (emitVpat) — US Section 508 / ITI Voluntary Product Accessibility Template, structured by WCAG 2.2 Success Criterion with per-criterion conformance level.
• EN 301 549 v3.2.1 §11 (emitEn301549) — ETSI harmonised standard conformance report covering WCAG-mapped clauses §11.1–§11.8.
• Swedish DOS-lagen (emitDosLagen) — Lag (2018:1937) accessibility-statement structure aligned with DIGG (Myndigheten för digital förvaltning) guidelines.

Every emitter is a pure function: same input → same output, no side effects. Each result carries a pinned $schema URI and schemaVersion literal so downstream consumers (queues, dashboards, regulator-portal uploads) can route on version. All three formats consume the same Violation shape, so a single scanner run can produce all three artefacts without re-aggregation.

What this package does NOT do

It does not scan, render HTML, render PDF, sign reports, post to regulator portals, or generate accessibility-statement landing pages. The output is JSON only — see @ariada-org/statement-generator for the EN 301 549 §7 HTML / MDX accessibility-statement renderer, and @ariada-org/vpat-html-renderer for the VPAT HTML view.

API summary

| Export | Signature | Returns | | -------------------------------------- | -------------------------------------------------------------- | ----------------------------------------------------------------- | | emitVpat(violations, meta) | (Violation[], ReportMeta) => VpatReport | VPAT 2.5 JSON — per-SC conformance rows | | emitEn301549(violations, meta) | (Violation[], ReportMeta) => En301549Report | EN 301 549 §11 conformance table | | emitDosLagen(violations, meta, opts) | (Violation[], ReportMeta, DosLagenOptions) => DosLagenReport | Swedish DOS-lagen statement object (Swedish-language fields) | | WCAG_22_CRITERIA | readonly WcagCriterion[] | Catalogue of all WCAG 2.2 Success Criteria (number, level, title) | | WCAG_BY_SC | Record<string, WcagCriterion> | SC-number lookup table |

Types: Violation, ReportMeta, VpatReport, VpatCriterion, VpatConformanceLevel, En301549Report, En301549Row, En301549Status, DosLagenReport, DosLagenStatus, DosLagenOptions.

Regulatory mapping

• VPAT 2.5 — ITI specification; structured per WCAG 2.2 Success Criteria + US Revised Section 508 (36 CFR Part 1194)
• EN 301 549 v3.2.1 — ETSI harmonised standard; §11.1–§11.8 cover WCAG 2.1 AA web mapping (extended here to WCAG 2.2 AA)
• DOS-lagen — Lag (2018:1937) om tillgänglighet till digital offentlig service; statement structure per DIGG guidelines
• Companion to Directive (EU) 2019/882 (EAA) Annex I §I.1 statement obligations and Directive (EU) 2016/2102 art. 7

Tests + verification

67 tests across 4 files (vitest), including 3 property-based suites via fast-check that verify structural invariants (schema URI stability, summary totals, per-SC cardinality). Run with pnpm test; coverage via pnpm test:coverage.

Sibling packages

• @ariada-org/wcag-rules-extended — produces the violations these emitters consume
• @ariada-org/statement-generator — renders accessibility-statement HTML/MDX from the same Violation + ReportMeta
• @ariada-org/vpat-html-renderer — renders VPAT HTML from emitVpat output

License

EUPL-1.2 — see LICENSE.