fix(markdown): parse link reference definitions with titles

patches/@tanstack__markdown@0.0.5.patch

@@ -0,0 +1,13 @@
+diff --git a/dist/parser.js b/dist/parser.js
+index 6616130a037737d109c527ec23ea8149ad8a68aa..1b4898b9ac1e749eeb136a5b8d13f8338a026b2b 100644
+--- a/dist/parser.js
++++ b/dist/parser.js
+@@ -334,7 +334,7 @@ function extractDefinitions(lines) {
+                 footnotes[normalizeReferenceLabel(label)] = { label, content: content.join('\n') };
+                 continue;
+             }
+-            const definition = line.match(/^ {0,3}\[([^\]\n]+)\]:[ \t]*(\S+)[ \t]*$/);
++            const definition = line.match(/^ {0,3}\[([^\]\n]+)\]:[ \t]*(\S+)(?:[ \t]+"[^"]*"|[ \t]+'[^']*'|[ \t]+\([^)]*\))?[ \t]*$/);
+             if (definition) {
+                 references[normalizeReferenceLabel(definition[1])] = { href: definition[2].replace(/^<|>$/g, '') };
+                 index++;

pnpm-workspace.yaml

@@ -33,3 +33,6 @@ allowBuilds:
 
   # Cloudflare Workers local runtime
   workerd: true
+
+patchedDependencies:
+  '@tanstack/markdown@0.0.5': patches/@tanstack__markdown@0.0.5.patch

tests/markdown-link-reference-definitions.test.ts

@@ -0,0 +1,43 @@
+import assert from 'node:assert/strict'
+import { parseSiteMarkdown } from '../src/utils/markdown'
+
+const markdownCases = [
+  {
+    name: 'single-quoted title',
+    markdown: "[//]: # 'SomeLabel'\n\nVisible content.",
+  },
+  {
+    name: 'double-quoted title',
+    markdown: '[//]: # "SomeLabel"\n\nVisible content.',
+  },
+  {
+    name: 'parenthesized title',
+    markdown: '[//]: # (SomeLabel)\n\nVisible content.',
+  },
+]
+
+for (const testCase of markdownCases) {
+  const document = parseSiteMarkdown(testCase.markdown)
+
+  assert.equal(
+    document.children.length,
+    1,
+    `${testCase.name} reference definition is not rendered`,
+  )
+
+  const paragraph = document.children[0]
+
+  assert.equal(paragraph?.type, 'paragraph', `${testCase.name} content remains`)
+
+  if (paragraph?.type !== 'paragraph') {
+    throw new Error(`${testCase.name} did not produce a paragraph`)
+  }
+
+  assert.deepEqual(
+    paragraph.children,
+    [{ type: 'text', value: 'Visible content.' }],
+    `${testCase.name} visible paragraph is preserved`,
+  )
+}
+
+console.log('markdown link reference definition tests passed')