From f1e8d4e70e2e224381c2d54feaa400fd686a5e33 Mon Sep 17 00:00:00 2001
From: Paul Bakaus <paul.bakaus@gmail.com>
Date: Mon, 31 Aug 2026 12:59:53 -0700
Subject: [PATCH] Simplify named rule extraction

AI-assisted by OpenAI Codex under maintainer pbakaus's scheduled-refactor authorization.
---
 skill/scripts/lib/design-parser.mjs | 48 +++++++++++------------------
 tests/design-parser.test.mjs        | 27 ++++++++++++++++
 2 files changed, 45 insertions(+), 30 deletions(-)

diff --git a/skill/scripts/lib/design-parser.mjs b/skill/scripts/lib/design-parser.mjs
index cab191d69..6f240a51e 100644
--- a/skill/scripts/lib/design-parser.mjs
+++ b/skill/scripts/lib/design-parser.mjs
@@ -329,47 +329,37 @@ function stripBold(s) {
 function extractNamedRules(lines) {
   const rules = [];
   const seen = new Set();
+  const addRule = (name, body, { allowDuplicate = false } = {}) => {
+    const key = name.toLowerCase();
+    if (!allowDuplicate && seen.has(key)) return;
+    seen.add(key);
+    rules.push({ name, body });
+  };
 
   // Style A (Impeccable): "**The X Rule.** body body body" — can span lines.
   const joined = lines.join('\n');
-  const inlineStart = /\*\*(The [^*]+?Rule)\.\*\*/g;
-  const inlineMatches = [];
-  let m;
-  while ((m = inlineStart.exec(joined)) !== null) {
-    inlineMatches.push({ name: m[1], start: m.index, end: inlineStart.lastIndex });
-  }
+  const inlineMatches = [...joined.matchAll(/\*\*(The [^*]+?Rule)\.\*\*/g)];
   for (let i = 0; i < inlineMatches.length; i++) {
-    const mm = inlineMatches[i];
-    const bodyEnd = i + 1 < inlineMatches.length ? inlineMatches[i + 1].start : joined.length;
+    const match = inlineMatches[i];
+    const bodyEnd = inlineMatches[i + 1]?.index ?? joined.length;
     const body = joined
-      .slice(mm.end, bodyEnd)
+      .slice(match.index + match[0].length, bodyEnd)
       .replace(/\n##[^\n]*$/s, '')
       .replace(/\n###[^\n]*$/s, '')
       .trim();
-    const name = stripBold(mm.name).trim();
-    seen.add(name.toLowerCase());
-    rules.push({ name, body: stripBold(body) });
+    // Preserve the inline format's historical behavior: repeated inline rules
+    // remain visible, while the later heading and bullet formats dedupe.
+    addRule(stripBold(match[1]).trim(), stripBold(body), { allowDuplicate: true });
   }
 
   // Style B (Stitch): `### The "X" Rule` or `### The X Fallback`, body is the
   // bullets/paragraphs until the next heading. Accept Rule / Fallback / Principle.
-  for (let i = 0; i < lines.length; i++) {
-    const h3 = lines[i].match(/^###\s+(.+?)\s*$/);
-    if (!h3) continue;
-    const headerName = stripBold(h3[1]).replace(/["“”]/g, '').trim();
+  for (const subsection of splitSubsections(lines).slice(1)) {
+    const headerName = stripBold(subsection.name).replace(/["“”]/g, '').trim();
     if (!/^The\b.*\b(Rule|Fallback|Principle)\b/i.test(headerName)) continue;
-    if (seen.has(headerName.toLowerCase())) continue;
 
-    const bodyLines = [];
-    for (let j = i + 1; j < lines.length; j++) {
-      if (/^##\s|^###\s/.test(lines[j])) break;
-      bodyLines.push(lines[j]);
-    }
-    const body = stripBold(bodyLines.join('\n').replace(/\n+/g, ' ')).trim();
-    if (body) {
-      seen.add(headerName.toLowerCase());
-      rules.push({ name: headerName, body });
-    }
+    const body = stripBold(subsection.lines.join('\n').replace(/\n+/g, ' ')).trim();
+    if (body) addRule(headerName, body);
   }
 
   // Style C (Stitch bullet form): "*   **The Layering Principle:** body"
@@ -379,9 +369,7 @@ function extractNamedRules(lines) {
     if (!mm) continue;
     const nameRaw = mm[1].replace(/[.:]\s*$/, '').replace(/["“”]/g, '').trim();
     if (!/^The\b.+\b(Rule|Fallback|Principle)$/i.test(nameRaw)) continue;
-    if (seen.has(nameRaw.toLowerCase())) continue;
-    seen.add(nameRaw.toLowerCase());
-    rules.push({ name: nameRaw, body: stripBold(mm[2]).trim() });
+    addRule(nameRaw, stripBold(mm[2]).trim());
   }
 
   return rules;
diff --git a/tests/design-parser.test.mjs b/tests/design-parser.test.mjs
index db78d4f12..a2cee5962 100644
--- a/tests/design-parser.test.mjs
+++ b/tests/design-parser.test.mjs
@@ -228,6 +228,33 @@ describe('parseDesignMd overview branch', () => {
   });
 });
 
+describe('parseDesignMd named rules', () => {
+  it('preserves format precedence while deduplicating later definitions', () => {
+    const md = `# Design System: Rules
+
+## Layout
+
+### The "Rhythm" Rule
+Ignore this duplicate heading definition.
+
+### The Fallback Principle
+Use the heading definition.
+
+### Named Rules
+- **The Fallback Principle:** Ignore this duplicate bullet definition.
+- **The Layering Principle:** Use the bullet definition.
+
+**The Rhythm Rule.** Keep the first definition.
+`;
+
+    assert.deepEqual(parseDesignMd(md).layout.rules, [
+      { name: 'The Rhythm Rule', body: 'Keep the first definition.' },
+      { name: 'The Fallback Principle', body: 'Use the heading definition.' },
+      { name: 'The Layering Principle', body: 'Use the bullet definition.' },
+    ]);
+  });
+});
+
 describe('parseDesignMd canonical sections', () => {
   it('preserves content and named rules from all eight canonical sections', () => {
     const md = `# Design System: Complete