feat(lint): add cta-hierarchy-mismatch rule to lintArtifact

apps/daemon/src/lint-artifact.ts

@@ -445,6 +445,15 @@ export function lintArtifact(rawHtml: unknown): LintFinding[] {
     });
   }
 
+  // ── P1-4: CTA hierarchy mismatch in commerce-critical regions ─────
+  // Read the artifact's own CSS to identify the primary button class
+  // (the first selector that paints a non-transparent background), then
+  // flag commerce CTAs in <header>/<nav>/<section class="hero"> whose
+  // class list doesn't include it. Advisory P1 — false positives are
+  // expected (outline CTA in header is a legitimate design choice).
+  const ctaFinding = detectCtaHierarchyMismatch(html);
+  if (ctaFinding) out.push(ctaFinding);
+
   // ── P2-1: missing comment-mode anchor on <section> ────────────────
   // Either `data-od-id` (web/mobile prototypes) or `data-screen-label`
   // (decks) counts. Whichever the artifact uses, every <section> should
@@ -998,3 +1007,226 @@ function isGlobalThemeScopeSelector(s: string): boolean {
   }
   return false;
 }
+
+const COMMERCE_CTA_VERBS = [
+  /\bbuy\b/i,
+  /\bpurchase\b/i,
+  /\bcheckout\b/i,
+  /\border\s+now\b/i,
+  /\bplace\s+order\b/i,
+  /\bplace\s+your\s+order\b/i,
+  /\bget\s+started\b/i,
+  /\bshop\s+now\b/i,
+  /\badd\s+to\s+cart\b/i,
+  /\bsubscribe\b/i,
+  /\bsign\s+up\b/i,
+  /\bstart\s+free\b/i,
+  /\bbook\s+now\b/i,
+  /\breserve\b/i,
+];
+
+const PRIMARY_NAME_HINTS = ['primary', 'cta', 'accent', 'buy', 'checkout'];
+
+function detectCtaHierarchyMismatch(html: string): LintFinding | null {
+  const primaryClass = findPrimaryButtonClass(html);
+  if (!primaryClass) return null;
+  const regions = extractCommerceRegions(html);
+  if (regions.length === 0) return null;
+  const offenders: string[] = [];
+  const seen = new Set<string>();
+  const ctaRe = /<(?:a|button)\b[^>]*\bclass\s*=\s*["']([^"']*)["'][^>]*>([\s\S]*?)<\/(?:a|button)>/gi;
+  for (const region of regions) {
+    for (const m of region.body.matchAll(ctaRe)) {
+      const classAttr = m[1] ?? '';
+      const text = stripTags(m[2] ?? '');
+      if (!isCommerceCtaText(text)) continue;
+      const classes = classAttr.split(/\s+/).filter(Boolean);
+      if (classes.includes(primaryClass)) continue;
+      const absolute = region.start + (m.index ?? 0);
+      const key = `cta:${absolute}`;
+      if (seen.has(key)) continue;
+      seen.add(key);
+      offenders.push(m[0]);
+    }
+  }
+  if (offenders.length === 0) return null;
+  const first = offenders[0] ?? '';
+  return {
+    severity: 'P1',
+    id: 'cta-hierarchy-mismatch',
+    message: `${offenders.length} commerce CTA(s) in header/nav/hero use a non-primary button class while .${primaryClass} is the page primary.`,
+    fix: `Promote the header/hero purchase or sign-up CTA to .${primaryClass}. If an outline CTA in the header is intentional, ignore this warning.`,
+    snippet: clip(first),
+  };
+}
+
+// Scan every <style> block (mirroring the all-caps-no-tracking rule) and
+// return the first class selector whose body paints a non-transparent
+// background. "First with a background" is preferred over "highest
+// specificity" because the linter has no DOM and cannot compute
+// specificity; the first painted button rule is a robust proxy for the
+// page primary across the templates this lint actually sees, and a name
+// hint (primary / cta / accent / buy / checkout) tiebreaks when multiple
+// candidates exist.
+function findPrimaryButtonClass(html: string): string | null {
+  const candidates: { name: string; hasColor: boolean }[] = [];
+  for (const block of html.matchAll(/<style[^>]*>([\s\S]*?)<\/style>/gi)) {
+    const css = (block[1] ?? '').replace(/\/\*[\s\S]*?\*\//g, '');
+    for (const m of css.matchAll(/([^{}]+)\{([^{}]*)\}/g)) {
+      const prelude = m[1] ?? '';
+      const body = m[2] ?? '';
+      const decls = parseDeclarations(body);
+      const bg = findLastDecl(decls, 'background') ?? findLastDecl(decls, 'background-color');
+      if (!bg) continue;
+      if (!isPaintedBackground(bg.value)) continue;
+      const hasColor = decls.some((d) => d.prop === 'color');
+      const classNames = extractSelectorClassNames(prelude);
+      for (const name of classNames) {
+        candidates.push({ name, hasColor });
+      }
+    }
+  }
+  if (candidates.length === 0) return null;
+  const interactiveClasses = collectInteractiveClasses(html);
+  const eligible = candidates.filter((c) => interactiveClasses.has(c.name));
+  if (eligible.length === 0) return null;
+  const hinted = eligible.find((c) =>
+    PRIMARY_NAME_HINTS.some((h) => c.name.toLowerCase().includes(h)),
+  );
+  if (hinted) return hinted.name;
+  const withColor = eligible.find((c) => c.hasColor);
+  return (withColor ?? eligible[0])?.name ?? null;
+}
+
+function collectInteractiveClasses(html: string): Set<string> {
+  const classes = new Set<string>();
+  for (const m of html.matchAll(/<(?:a|button)\b[^>]*\bclass\s*=\s*["']([^"']*)["']/gi)) {
+    for (const token of (m[1] ?? '').split(/\s+/)) {
+      if (token) classes.add(token);
+    }
+  }
+  return classes;
+}
+
+function extractSelectorClassNames(prelude: string): string[] {
+  const out: string[] = [];
+  const seen = new Set<string>();
+  for (const branch of prelude.split(',')) {
+    for (const tok of branch.matchAll(/\.([a-zA-Z][\w-]*)/g)) {
+      const name = tok[1];
+      if (!name || seen.has(name)) continue;
+      seen.add(name);
+      out.push(name);
+    }
+  }
+  return out;
+}
+
+function extractBalancedArgs(value: string, from: number): string | null {
+  let depth = 1;
+  for (let i = from; i < value.length; i++) {
+    const ch = value[i];
+    if (ch === '(') depth++;
+    else if (ch === ')') {
+      depth--;
+      if (depth === 0) return value.slice(from, i);
+    }
+  }
+  return null;
+}
+
+function findTopLevelSlash(args: string): number {
+  let depth = 0;
+  for (let i = args.length - 1; i >= 0; i--) {
+    const ch = args[i];
+    if (ch === ')') depth++;
+    else if (ch === '(') depth--;
+    else if (ch === '/' && depth === 0) return i;
+  }
+  return -1;
+}
+
+function splitTopLevel(args: string, sep: string): string[] {
+  const out: string[] = [];
+  let depth = 0;
+  let start = 0;
+  for (let i = 0; i < args.length; i++) {
+    const ch = args[i];
+    if (ch === '(') depth++;
+    else if (ch === ')') depth--;
+    else if (ch === sep && depth === 0) {
+      out.push(args.slice(start, i).trim());
+      start = i + 1;
+    }
+  }
+  out.push(args.slice(start).trim());
+  return out;
+}
+
+function parseAlpha(token: string | undefined): number | null {
+  if (!token) return null;
+  const trimmed = token.trim();
+  const calc = /^calc\(\s*(-?\d+(?:\.\d+)?)\s*%?\s*\)$/i.exec(trimmed);
+  if (calc) {
+    const n = Number.parseFloat(calc[1] ?? '');
+    return Number.isFinite(n) ? n : null;
+  }
+  const n = Number.parseFloat(trimmed);
+  return Number.isFinite(n) ? n : null;
+}
+
+function isPaintedBackground(value: string): boolean {
+  const v = value.trim().toLowerCase();
+  if (!v) return false;
+  if (v === 'transparent' || v === 'none' || v === 'inherit' || v === 'initial' || v === 'unset') return false;
+  if (/^#[0-9a-f]{3,8}\b/.test(v)) return true;
+  if (/var\(--[\w-]+/.test(v)) return true;
+  if (/^rgb\(|^rgba\(|^hsl\(|^hsla\(/.test(v)) {
+    const fnMatch = v.match(/^(rgba?|hsla?)\(/);
+    if (!fnMatch) return true;
+    const fn = fnMatch[1];
+    const args = extractBalancedArgs(v, fnMatch[0].length);
+    if (args === null) return true;
+    const slashIdx = findTopLevelSlash(args);
+    if (slashIdx >= 0) {
+      const alpha = parseAlpha(args.slice(slashIdx + 1));
+      if (alpha === null) return true;
+      return alpha !== 0;
+    }
+    const parts = splitTopLevel(args, ',');
+    if ((fn === 'rgba' || fn === 'hsla') && parts.length === 4) {
+      const alpha = parseAlpha(parts[3]);
+      if (alpha === null) return true;
+      return alpha !== 0;
+    }
+    return true;
+  }
+  if (/^linear-gradient\(|^radial-gradient\(/.test(v)) return true;
+  return false;
+}
+
+function extractCommerceRegions(html: string): { body: string; start: number }[] {
+  const regions: { body: string; start: number }[] = [];
+  const patterns = [
+    /<header\b[^>]*>([\s\S]*?)<\/header>/gi,
+    /<nav\b[^>]*>([\s\S]*?)<\/nav>/gi,
+    /<section\b[^>]*\bclass\s*=\s*["'][^"']*\bhero\b[^"']*["'][^>]*>([\s\S]*?)<\/section>/gi,
+  ];
+  for (const re of patterns) {
+    for (const m of html.matchAll(re)) {
+      const body = m[1];
+      if (!body) continue;
+      const start = (m.index ?? 0) + m[0].indexOf(body);
+      regions.push({ body, start });
+    }
+  }
+  return regions;
+}
+
+function isCommerceCtaText(text: string): boolean {
+  return COMMERCE_CTA_VERBS.some((re) => re.test(text));
+}
+
+function stripTags(s: string): string {
+  return s.replace(/<[^>]*>/g, ' ').replace(/\s+/g, ' ').trim();
+}