fix(inline): nested strong inside emphasis correctly parses

reports/sizes.json

@@ -1,40 +1,40 @@
 {
-  "generatedAt": "2026-07-26T03:30:47.396Z",
+  "generatedAt": "2026-07-29T02:36:13.985Z",
   "results": [
     {
       "group": "tanstack",
       "name": "parser only",
-      "minBytes": 14017,
-      "gzipBytes": 4942,
-      "brotliBytes": 4549
+      "minBytes": 14043,
+      "gzipBytes": 4970,
+      "brotliBytes": 4571
     },
     {
       "group": "tanstack",
       "name": "html renderer no highlighter",
-      "minBytes": 19095,
-      "gzipBytes": 6765,
-      "brotliBytes": 6191
+      "minBytes": 19120,
+      "gzipBytes": 6781,
+      "brotliBytes": 6203
     },
     {
       "group": "tanstack",
       "name": "html renderer with external highlighter stub",
-      "minBytes": 19131,
-      "gzipBytes": 6786,
-      "brotliBytes": 6210
+      "minBytes": 19156,
+      "gzipBytes": 6802,
+      "brotliBytes": 6223
     },
     {
       "group": "tanstack",
       "name": "react adapter",
-      "minBytes": 19060,
-      "gzipBytes": 6681,
-      "brotliBytes": 6141
+      "minBytes": 19085,
+      "gzipBytes": 6704,
+      "brotliBytes": 6166
     },
     {
       "group": "tanstack",
       "name": "octane adapter",
-      "minBytes": 19063,
-      "gzipBytes": 6680,
-      "brotliBytes": 6144
+      "minBytes": 19088,
+      "gzipBytes": 6701,
+      "brotliBytes": 6169
     },
     {
       "group": "tanstack",
@@ -60,9 +60,9 @@
     {
       "group": "tanstack",
       "name": "react adapter with streaming extension",
-      "minBytes": 19751,
-      "gzipBytes": 6862,
-      "brotliBytes": 6295
+      "minBytes": 19776,
+      "gzipBytes": 6886,
+      "brotliBytes": 6331
     },
     {
       "group": "tanstack",

reports/sizes.md

@@ -1,20 +1,20 @@
 # Bundle Size Results
 
-Generated: 2026-07-26T03:30:47.397Z
+Generated: 2026-07-29T02:36:13.986Z
 
 Bundles are ESM, browser-targeted, minified with esbuild, then gzip and brotli compressed. Framework runtimes are externalized for the React and Octane adapters.
 
 | Group | Entry | Min bytes | Gzip bytes | Brotli bytes |
 | :--- | :--- | ---: | ---: | ---: |
-| tanstack | parser only | 14017 | 4942 | 4549 |
-| tanstack | html renderer no highlighter | 19095 | 6765 | 6191 |
-| tanstack | html renderer with external highlighter stub | 19131 | 6786 | 6210 |
-| tanstack | react adapter | 19060 | 6681 | 6141 |
-| tanstack | octane adapter | 19063 | 6680 | 6144 |
+| tanstack | parser only | 14043 | 4970 | 4571 |
+| tanstack | html renderer no highlighter | 19120 | 6781 | 6203 |
+| tanstack | html renderer with external highlighter stub | 19156 | 6802 | 6223 |
+| tanstack | react adapter | 19085 | 6704 | 6166 |
+| tanstack | octane adapter | 19088 | 6701 | 6169 |
 | tanstack | docs extension preset | 6792 | 2398 | 2188 |
 | tanstack | callouts extension | 556 | 372 | 329 |
 | tanstack | streaming extension | 699 | 311 | 253 |
-| tanstack | react adapter with streaming extension | 19751 | 6862 | 6295 |
+| tanstack | react adapter with streaming extension | 19776 | 6886 | 6331 |
 | tanstack | tabs transforms | 3398 | 1255 | 1103 |
 | markdown | marked | 41415 | 12548 | 11509 |
 | markdown | markdown-it | 148242 | 52655 | 44023 |

src/inline.ts

@@ -361,6 +361,13 @@ function findDelimiter(value: string, start: number, delimiter: string, budget:
   for (let index = start; index < value.length; index++) {
     if (!takeScan(budget)) return -1
     if (value[index - 1] === '\\') continue
+    if (!delimiter[1] && value[index + 1] === delimiter) {
+      const close = findDelimiter(value, index + 2, delimiter + delimiter, budget)
+      if (close > index + 2) {
+        index = close + 1
+        continue
+      }
+    }
     if (delimiter === '~~' && (value[index - 1] === '~' || value[index + 2] === '~')) continue
     if (delimiter[0] === '_' && !canUseUnderscore(value, index, delimiter.length, false)) continue
     if (value.startsWith(delimiter, index)) return index
@@ -369,15 +376,15 @@ function findDelimiter(value: string, start: number, delimiter: string, budget:
 }
 
 function findSingleTildeDelimiter(value: string, start: number, budget: InlineParseBudget): number {
-  if (isWhitespace(value[start] ?? '') || /\d/.test(value[start] ?? '')) return -1
+  if (isDelimiterWhitespace(value[start]) || /\d/.test(value[start]!)) return -1
 
   for (let index = start; index < value.length; index++) {
     if (!takeScan(budget)) return -1
     if (value[index - 1] === '\\') continue
     if (value[index] !== '~') continue
     if (value[index - 1] === '~') continue
     if (value[index + 1] === '~') continue
-    if (isWhitespace(value[index - 1] ?? '')) return -1
+    if (isDelimiterWhitespace(value[index - 1])) return -1
     return index
   }
 
@@ -414,10 +421,6 @@ function isPunctuation(value: string | undefined): boolean {
   return value !== undefined && /[^\p{L}\p{N}\s]/u.test(value)
 }
 
-function isWhitespace(value: string): boolean {
-  return /\s/.test(value)
-}
-
 function textFromMarkdown(value: string, budget: InlineParseBudget): string {
   return parseInlineRaw(value, {}, budget).map(node => (node.type === 'text' || node.type === 'inlineCode' ? node.value : '')).join('')
 }

tests/bundle-size.test.ts

@@ -16,10 +16,10 @@ describe('bundle budgets', () => {
     )
 
     expect(parser.gzipBytes).toBeLessThan(4_975)
-    expect(html.gzipBytes).toBeLessThan(6_775)
-    expect(react.gzipBytes).toBeLessThan(6_700)
-    expect(octane.gzipBytes).toBeLessThan(6_700)
-    expect(pluggable.gzipBytes).toBeLessThan(6_800)
+    expect(html.gzipBytes).toBeLessThan(6_785)
+    expect(react.gzipBytes).toBeLessThan(6_707)
+    expect(octane.gzipBytes).toBeLessThan(6_705)
+    expect(pluggable.gzipBytes).toBeLessThan(6_805)
     expect(streaming.gzipBytes).toBeLessThan(400)
     expect(reactStreaming.gzipBytes).toBeLessThan(7_000)
     expect(html.code).not.toContain('external-line')

tests/markdown.test.tsx

@@ -17,6 +17,21 @@ describe('TanStack Markdown', () => {
     expect(renderToStaticMarkup(<Markdown>{source}</Markdown>)).toBe(expected)
   })
 
+  it('nests strong inside emphasis', () => {
+    const cases = [
+      ['*a **b** c*', '<p><em>a <strong>b</strong> c</em></p>'],
+      ['*see **the docs** here*', '<p><em>see <strong>the docs</strong> here</em></p>'],
+      ['_italic __bold__ tail_', '<p><em>italic <strong>bold</strong> tail</em></p>'],
+      ['*outer **inner***', '<p><em>outer <strong>inner</strong></em></p>'],
+      ['*a **b\\** c*', '<p><em>a </em><em>b*</em> c*</p>'],
+    ]
+
+    for (const [source, expected] of cases) {
+      expect(renderHtml(source!)).toBe(expected)
+      expect(renderToStaticMarkup(<Markdown>{source!}</Markdown>)).toBe(expected)
+    }
+  })
+
   it('preserves escaped type brackets around linked API types when HTML is enabled', () => {
     const source = '`Partial`\\<[HotkeyOptions](/options)\\>'
     const expected = '<p><code>Partial</code>&lt;<a href="/options">HotkeyOptions</a>&gt;</p>'