feat(markdown): add languageLabel config and improve languageAlias display

src/node/markdown/markdown.ts

@@ -88,11 +88,24 @@ export interface MarkdownOptions extends Options {
   languages?: (LanguageInput | BuiltinLanguage)[]
   /**
    * Custom language aliases.
+   * Maps custom language names to existing languages for syntax highlighting.
+   * Language identifiers with underscores will automatically display with spaces.
+   * Alias lookup is case-insensitive.
+   *
+   * @example { 'my_lang': 'python' } 
+   * 
+   * ```My_Lang uses Python highlighting, displays "My Lang"
    *
-   * @example { 'my-lang': 'js' }
    * @see https://shiki.style/guide/load-lang#custom-language-aliases
    */
   languageAlias?: Record<string, string>
+  /**
+   * Custom language labels for display.
+   * Overrides the default language label shown in code blocks.
+   *
+   * @example { 'vue': 'Vue SFC' }
+   */
+  languageLabel?: Record<string, string>
   /**
    * Show line numbers in code blocks
    * @default false
@@ -249,7 +262,10 @@ export async function createMarkdownRenderer(
   // custom plugins
   md.use(componentPlugin, { ...options.component })
     .use(highlightLinePlugin)
-    .use(preWrapperPlugin, { codeCopyButtonTitle })
+    .use(preWrapperPlugin, {
+      codeCopyButtonTitle,
+      languageLabel: options.languageLabel
+    })
     .use(snippetPlugin, srcDir)
     .use(containerPlugin, options.container)
     .use(imagePlugin, options.image)

src/node/markdown/plugins/highlight.ts

@@ -68,7 +68,10 @@ export async function highlight(
       ...(options.languages || []),
       ...Object.values(options.languageAlias || {})
     ],
-    langAlias: options.languageAlias
+    langAlias: options.languageAlias ?
+      Object.fromEntries(
+        Object.entries(options.languageAlias).map(([key, value]) => [key.toLowerCase(), value])
+      ) : undefined
   })
 
   await options?.shikiSetup?.(highlighter)

src/node/markdown/plugins/preWrapper.ts

@@ -2,6 +2,7 @@ import type { MarkdownItAsync } from 'markdown-it-async'
 
 export interface Options {
   codeCopyButtonTitle: string
+  languageLabel?: Record<string, string>
 }
 
 export function preWrapperPlugin(md: MarkdownItAsync, options: Options) {
@@ -17,11 +18,12 @@ export function preWrapperPlugin(md: MarkdownItAsync, options: Options) {
     token.info = token.info.replace(/ active$/, '').replace(/ active /, ' ')
 
     const lang = extractLang(token.info)
+    const langLabel = getLangLabel(lang, options.languageLabel)
 
     return (
       `<div class="language-${lang}${active}">` +
       `<button title="${options.codeCopyButtonTitle}" class="copy"></button>` +
-      `<span class="lang">${lang}</span>` +
+      `<span class="lang">${langLabel}</span>` +
       fence(...args) +
       '</div>'
     )
@@ -46,3 +48,11 @@ function extractLang(info: string) {
     .replace(/^vue-html$/, 'template')
     .replace(/^ansi$/, '')
 }
+
+function getLangLabel(lang: string, languageLabel?: Record<string, string>): string {
+  if (languageLabel && languageLabel[lang]) {
+    return languageLabel[lang]
+  }
+
+  return lang.replace(/_/g, ' ')
+}