fix: handle bracketed spans inside link labels (#288)

Co-authored-by: Farnabaz <farnabaz@gmail.com>

Author: deshiknaves

packages/comark/SPEC/COMARK/link-with-span.md

@@ -0,0 +1,76 @@
+## Input
+
+```md
+[[1]{} Document](#)
+
+[[link-name]{.cls} more](https://example.com)
+```
+
+## AST
+
+```json
+
+{
+   "frontmatter":{
+      
+   },
+   "meta":{
+      
+   },
+   "nodes":[
+      [
+         "p",
+         {
+            
+         },
+         [
+            "a",
+            {
+               "href":"#"
+            },
+            [
+              "span",
+              {},
+              "1"
+            ],
+            " Document"
+         ]
+      ],
+      [
+         "p",
+         {
+            
+         },
+         [
+            "a",
+            {
+               "href":"https://example.com"
+            },
+            [
+              "span",
+              {
+                "class": "cls"
+              },
+              "link-name"
+            ],
+            " more"
+         ]
+      ]
+   ]
+}
+```
+
+## HTML
+
+```html
+<p><a href="#"><span>1</span> Document</a></p>
+<p><a href="https://example.com"><span class="cls">link-name</span> more</a></p>
+```
+
+## Markdown
+
+```md
+[[1]{} Document](#)
+
+[[link-name]{.cls} more](https://example.com)
+```

packages/comark/SPEC/common-mark/links.md

@@ -0,0 +1,82 @@
+## Input
+
+```md
+[Document](#)
+
+[[1] Document](#)
+
+[[link-name] more](https://example.com)
+```
+
+## AST
+
+```json
+
+{
+   "frontmatter":{
+      
+   },
+   "meta":{
+      
+   },
+   "nodes":[
+      [
+         "p",
+         {
+            
+         },
+         [
+            "a",
+            {
+               "href":"#"
+            },
+            "Document"
+         ]
+      ],
+      [
+         "p",
+         {
+            
+         },
+         [
+            "a",
+            {
+               "href":"#"
+            },
+            "[1] Document"
+         ]
+      ],
+      [
+         "p",
+         {
+            
+         },
+         [
+            "a",
+            {
+               "href":"https://example.com"
+            },
+            "[link-name] more"
+         ]
+      ]
+   ]
+}
+```
+
+## HTML
+
+```html
+<p><a href="#">Document</a></p>
+<p><a href="#">[1] Document</a></p>
+<p><a href="https://example.com">[link-name] more</a></p>
+```
+
+## Markdown
+
+```md
+[Document](#)
+
+[\[1\] Document](#)
+
+[\[link-name\] more](https://example.com)
+```

packages/comark/src/internal/stringify/handlers/mdc.ts

@@ -36,9 +36,14 @@ export async function mdc(node: ComarkElement, state: State, parent?: ComarkElem
   }
   content = content.trimEnd()
 
-  const attrs = attributeEntries.length > 0 ? comarkAttributes(attributes) : ''
+  let attrs = attributeEntries.length > 0 ? comarkAttributes(attributes) : ''
 
   if (tag === 'span') {
+    if (!attrs && parent?.[0] == 'a') {
+      // Add empty attributes syntax to end of spans inside Anchor links
+      // This will force Comark to parse them as span and prevent conflict
+      attrs ||= '{}'
+    }
     return `[${content}]${attrs}` + (inline ? '' : state.context.blockSeparator)
   }
 

packages/comark/src/plugins/syntax.ts

@@ -449,7 +449,12 @@ const markdownItInlineSpan: PluginSimple = (md) => {
     const nextChar = state.src[index + 1]
     if (nextChar === '(' || nextChar === '[') return false
 
-    if (silent) return true
+    // Inside a link label, bare `[text]` stays literal (plain-markdown behavior,
+    // e.g. `[[1] Document](#)`); only an explicit `[text]{attrs}` span matches
+    if (state.linkLevel > 0 && nextChar !== '{') return false
+
+    // Returning `false` lets `parseLinkLabel`'s own depth tracking consume nested brackets and the outer link parse
+    if (silent) return false
 
     state.push('mdc_inline_span', 'span', 1)