handle custom slugify

src/node/markdown/markdown.ts

@@ -242,7 +242,8 @@ export async function createMarkdownRenderer(
     .use(
       linkPlugin,
       { target: '_blank', rel: 'noreferrer', ...options.externalLinks },
-      base
+      base,
+      options.anchor?.slugify ?? slugify
     )
     .use(lineNumberPlugin, options.lineNumbers)
 

src/node/markdown/plugins/link.ts

@@ -16,7 +16,8 @@ const indexRE = /(^|.*\/)index.md(#?.*)$/i
 export const linkPlugin = (
   md: MarkdownItAsync,
   externalAttrs: Record<string, string>,
-  base: string
+  base: string,
+  slugify: (str: string) => string
 ) => {
   md.renderer.rules.link_open = (
     tokens,
@@ -27,9 +28,12 @@ export const linkPlugin = (
   ) => {
     const token = tokens[idx]
     const hrefIndex = token.attrIndex('href')
-    const targetIndex = token.attrIndex('target')
+    if (
-    const downloadIndex = token.attrIndex('download')
+      hrefIndex >= 0 &&
-    if (hrefIndex >= 0 && targetIndex < 0 && downloadIndex < 0) {
+      token.attrIndex('target') < 0 &&
+      token.attrIndex('download') < 0 &&
+      token.attrGet('class') !== 'header-anchor' // header anchors are already normalized
+    ) {
       const hrefAttr = token.attrs![hrefIndex]
       const url = hrefAttr[1]
       if (isExternal(url)) {
@@ -54,9 +58,7 @@ export const linkPlugin = (
         ) {
           normalizeHref(hrefAttr, env)
         } else if (url.startsWith('#')) {
-          hrefAttr[1] = decodeURI(hrefAttr[1])
+          hrefAttr[1] = decodeURI(normalizeHash(hrefAttr[1]))
-            .normalize('NFKD')
-            .replace(/[\u0300-\u036F]/g, '')
         }
 
         // append base to internal (non-relative) urls
@@ -74,7 +76,7 @@ export const linkPlugin = (
     const indexMatch = url.match(indexRE)
     if (indexMatch) {
       const [, path, hash] = indexMatch
-      url = path + hash.normalize('NFKD').replace(/[\u0300-\u036F]/g, '')
+      url = path + normalizeHash(hash)
     } else {
       let cleanUrl = url.replace(/[?#].*$/, '')
       // transform foo.md -> foo[.html]
@@ -90,10 +92,7 @@ export const linkPlugin = (
         cleanUrl += '.html'
       }
       const parsed = new URL(url, 'http://a.com')
-      url =
+      url = cleanUrl + parsed.search + normalizeHash(parsed.hash)
-        cleanUrl +
-        parsed.search +
-        parsed.hash.normalize('NFKD').replace(/[\u0300-\u036F]/g, '')
     }
 
     // ensure leading . for relative paths
@@ -108,6 +107,10 @@ export const linkPlugin = (
     hrefAttr[1] = decodeURI(url)
   }
 
+  function normalizeHash(str: string) {
+    return str ? encodeURI('#' + slugify(decodeURI(str).slice(1))) : ''
+  }
+
   function pushLink(link: string, env: MarkdownEnv) {
     const links = env.links || (env.links = [])
     links.push(link)