fix: custom titles of code snippets inside code groups (#1834)

Co-authored-by: Divyansh Singh <40380293+brc-dd@users.noreply.github.com>

docs/guide/markdown.md

@@ -651,6 +651,34 @@ export default config
 
 :::
 
+You can also [import snippets](#import-code-snippets) in code groups:
+
+**Input**
+
+```md
+::: code-group
+
+<!-- filename is used as title by default -->
+
+<<< @/snippets/snippet.js
+
+<!-- you can provide a custom one too -->
+
+<<< @/snippets/snippet-with-region.js#snippet{1,2 ts:line-numbers} [snippet with region]
+
+:::
+```
+
+**Output**
+
+::: code-group
+
+<<< @/snippets/snippet.js
+
+<<< @/snippets/snippet-with-region.js#snippet{1,2 ts:line-numbers} [snippet with region]
+
+:::
+
 ## Markdown File Inclusion
 
 You can include a markdown file in another markdown file like this:

src/node/markdown/plugins/lineNumbers.ts

@@ -24,8 +24,13 @@ export const lineNumberPlugin = (md: MarkdownIt, enable = false) => {
     )
 
     const lines = code.split('\n')
-    const lineNumbersCode = [...Array(lines.length - 1)]
-      .map((line, index) => `<span class="line-number">${index + 1}</span><br>`)
+
+    const lineNumbersCode = [
+      ...Array(
+        lines.length - (lines.at(-1) === `<span class="line"></span>` ? 1 : 0)
+      )
+    ]
+      .map((_, index) => `<span class="line-number">${index + 1}</span><br>`)
       .join('')
 
     const lineNumbersWrapperCode = `<div class="line-numbers-wrapper" aria-hidden="true">${lineNumbersCode}</div>`

src/node/markdown/plugins/preWrapper.ts

@@ -3,11 +3,15 @@ import type MarkdownIt from 'markdown-it'
 export function preWrapperPlugin(md: MarkdownIt) {
   const fence = md.renderer.rules.fence!
   md.renderer.rules.fence = (...args) => {
-    const { info } = args[0][args[1]]
-    const lang = extractLang(info)
+    const [tokens, idx] = args
+    const token = tokens[idx]
+    // remove title from info
+    token.info = token.info.replace(/\[.*\]/, '')
+
+    const lang = extractLang(token.info)
     const rawCode = fence(...args)
     return `<div class="language-${lang}${
-      / active( |$)/.test(info) ? ' active' : ''
+      / active( |$)/.test(token.info) ? ' active' : ''
     }"><button title="Copy Code" class="copy"></button><span class="lang">${lang}</span>${rawCode}</div>`
   }
 }
@@ -19,7 +23,7 @@ export function extractTitle(info: string) {
 const extractLang = (info: string) => {
   return info
     .trim()
-    .replace(/:(no-)?line-numbers$/, '')
+    .replace(/:(no-)?line-numbers({| |$).*/, '')
     .replace(/(-vue|{| ).*$/, '')
     .replace(/^vue-html$/, 'template')
 }

src/node/markdown/plugins/snippet.ts

@@ -95,10 +95,10 @@ export const snippetPlugin = (md: MarkdownIt, srcDir: string) => {
      *    where #region and {meta} are optional
      *    and meta can be like '1,2,4-6 lang', 'lang' or '1,2,4-6'
      *
-     * captures: ['/path/to/file.extension', 'extension', '#region', '{meta}']
+     * captures: ['/path/to/file.extension', 'extension', '#region', '{meta}', '[title]']
      */
     const rawPathRegexp =
-      /^(.+(?:\.([a-z0-9]+)))(?:(#[\w-]+))?(?: ?(?:{(\d+(?:[,-]\d+)*)? ?(\S+)?}))?$/
+      /^(.+(?:\.([a-z0-9]+)))(?:(#[\w-]+))?(?: ?(?:{(\d+(?:[,-]\d+)*)? ?(\S+)?}))? ?(?:\[(.+)\])?$/
 
     const rawPath = state.src
       .slice(start, end)
@@ -106,13 +106,23 @@ export const snippetPlugin = (md: MarkdownIt, srcDir: string) => {
       .replace(/^@/, srcDir)
       .trim()
 
-    const [filename = '', extension = '', region = '', lines = '', lang = ''] =
-      (rawPathRegexp.exec(rawPath) || []).slice(1)
+    const [
+      filename = '',
+      extension = '',
+      region = '',
+      lines = '',
+      lang = '',
+      rawTitle = ''
+    ] = (rawPathRegexp.exec(rawPath) || []).slice(1)
+
+    const title = rawTitle || filename.split('/').at(-1) || ''
 
     state.line = startLine + 1
 
     const token = state.push('fence', 'code', 0)
-    token.info = `${lang || extension}${lines ? `{${lines}}` : ''}`
+    token.info = `${lang || extension}${lines ? `{${lines}}` : ''}${
+      title ? `[${title}]` : ''
+    }`
 
     // @ts-ignore
     token.src = path.resolve(filename) + region