fix: skip _ inside attributes when only the attributes plugin is on

auto-close treated {target="_blank"} as italic and appended _. Enable attribute-brace skipping whenever the attributes plugin is registered, without turning on component fences.

Co-authored-by: Yuzhong Zhang <BetterAndBetterII@users.noreply.github.com>

Author: BetterAndBetterII

packages/comark/src/internal/parse/auto-close/index.ts

@@ -13,12 +13,18 @@ import { closeTables } from './table.ts'
  * @param options - `frontmatter` completes an unclosed leading frontmatter block.
  *   `syntax: false` disables Comark component-fence handling (`::` closers and
  *   props braces), for input parsed without the components plugin.
+ *   `attributes: true` still treats `{...}` as an attribute scope (so `_` / `*`
+ *   inside values are not closed) without enabling component fences.
  * @returns The markdown with unclosed syntax closed
  */
-export function autoCloseMarkdown(markdown: string, options: { frontmatter?: boolean; syntax?: boolean } = {}): string {
+export function autoCloseMarkdown(
+  markdown: string,
+  options: { frontmatter?: boolean; syntax?: boolean; attributes?: boolean } = {}
+): string {
   if (!markdown || markdown === '') return markdown
 
   const syntaxEnabled = options.syntax !== false
+  const attributesEnabled = options.attributes ?? syntaxEnabled
 
   const lines = markdown.split('\n')
   const n = lines.length
@@ -152,7 +158,7 @@ export function autoCloseMarkdown(markdown: string, options: { frontmatter?: boo
   // Fix inline markers on last line (skip inside block-level structures)
   const lastIdx = n - 1
   if (!inFrontmatter && !inBlockMath && lines[lastIdx].trim() !== '$$') {
-    lines[lastIdx] = closeInlineMarkersLinear(lines[lastIdx], syntaxEnabled)
+    lines[lastIdx] = closeInlineMarkersLinear(lines[lastIdx], attributesEnabled)
   }
 
   let result = lines.join('\n')
@@ -256,9 +262,9 @@ function scanDelimiterRun(line: string, start: number, marker: string) {
  * Closes inline markers (*, **, ***, ~~, `, $, $$, [, () on the last line
  * without using regex - pure character scanning in O(n) time
  *
- * With `syntax` false, `{...}` is literal text instead of an attribute scope.
+ * With `attributesEnabled` false, `{...}` is literal text instead of an attribute scope.
  */
-function closeInlineMarkersLinear(line: string, syntax: boolean): string {
+function closeInlineMarkersLinear(line: string, attributesEnabled: boolean): string {
   const len = line.length
   if (len === 0) return line
 
@@ -318,11 +324,11 @@ function closeInlineMarkersLinear(line: string, syntax: boolean): string {
       continue
     }
 
-    if (syntax && ch === '{' && prevCh !== ' ') {
+    if (attributesEnabled && ch === '{' && prevCh !== ' ') {
       inAttributes++
       continue
     }
-    if (syntax && ch === '}') {
+    if (attributesEnabled && ch === '}') {
       if (inAttributes > 0) inAttributes--
       continue
     }

packages/comark/src/parse.ts

@@ -144,6 +144,7 @@ export function createMarkdownParser<const TPlugins extends readonly ComarkPlugi
           autoCloseMarkdown(state.markdown, {
             frontmatter: hasPlugin('frontmatter') && opts.streaming,
             syntax: hasPlugin('components'),
+            attributes: hasPlugin('components') || hasPlugin('attributes'),
           })
         )
       }

packages/comark/test/auto-close.test.ts

@@ -775,6 +775,19 @@ describe('autoCloseMarkdown - syntax option', () => {
     expect(autoCloseMarkdown('text{.cls **bold', { syntax: false })).toBe('text{.cls **bold**')
   })
 
+  it('skips _ inside attribute values when attributes are enabled without component syntax', () => {
+    expect(
+      autoCloseMarkdown('this is a [link with an attribute](https://example.com){target="_blank"}', {
+        syntax: false,
+        attributes: true,
+      })
+    ).toBe('this is a [link with an attribute](https://example.com){target="_blank"}')
+  })
+
+  it('does not treat unclosed :: as a component when only attributes are enabled', () => {
+    expect(autoCloseMarkdown('::alert\nContent', { syntax: false, attributes: true })).toBe('::alert\nContent')
+  })
+
   it('still completes frontmatter with syntax: false', () => {
     expect(autoCloseMarkdown('---\ntitle: Hello', { frontmatter: true, syntax: false })).toBe('---\ntitle: Hello\n---')
   })

packages/comark/test/plugins/default-plugins.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it, vi } from 'vitest'
 import { parseMarkdown } from '../../src/parse'
+import attributes from '../../src/plugins/attributes'
 import components from '../../src/plugins/components'
 import frontmatter from '../../src/plugins/frontmatter'
 import html from '../../src/plugins/html'
@@ -128,5 +129,27 @@ describe('default plugin options', () => {
       })
       expect(tree.nodes).toEqual([['alert', {}, 'Content']])
     })
+
+    it('renders attributes when only attributes enabled', async () => {
+      const tree = await parseMarkdown('this is a [link with an attribute](https://example.com){target="_blank"}', {
+        registerDefaultPlugins: false,
+        plugins: [attributes()],
+      })
+      expect(tree.nodes).toEqual([
+        [
+          'p',
+          {},
+          'this is a ',
+          [
+            'a',
+            {
+              href: 'https://example.com',
+              target: '_blank',
+            },
+            'link with an attribute',
+          ],
+        ],
+      ])
+    })
   })
 })