feat: use rehype-external-links

package.json

@@ -58,6 +58,7 @@
     "mdast-util-gfm-strikethrough": "^2.0.0",
     "micromark-extension-gfm-strikethrough": "^2.0.0",
     "micromark-util-combine-extensions": "^2.0.0",
+    "rehype-external-links": "^3.0.0",
     "rehype-format": "^5.0.0",
     "rehype-parse": "^9.0.0",
     "rehype-raw": "^7.0.0",

src/transformers/html2md2html.test.ts

@@ -271,7 +271,7 @@ describe('HTML to Markdown: Basic Formats', () => {
   test('link', () => {
     html2md2html(
       `
-      <p>My favorite search engine is <a href="https://duckduckgo.com" target="_blank">Duck Duck Go</a>.</p>
+      <p>My favorite search engine is <a href="https://duckduckgo.com" target="_blank" rel="noopener nofollow noreferrer">Duck Duck Go</a>.</p>
       `,
       'My favorite search engine is [Duck Duck Go](https://duckduckgo.com).',
     )
@@ -291,7 +291,7 @@ describe('HTML to Markdown: Basic Formats', () => {
     html2md2html(
       `
       <p>
-        <a href="https://www.flickr.com/photos/beaurogers/31833779864/in/abc.png" target="_blank">
+        <a href="https://www.flickr.com/photos/beaurogers/31833779864/in/abc.png" target="_blank" rel="noopener nofollow noreferrer">
           <img src="https://mdg.imgix.net/assets/images/shiprock.jpg" alt="An old rock in the desert" title="Shiprock, New Mexico by Beau Rogers" />
         </a>
       </p>
@@ -376,7 +376,7 @@ describe('HTML to Markdown: Full Content', () => {
       <p>Dolore labore laboris <strong>consequat nostrud</strong> Lorem irure excepteur incididunt adipisicing id.</p>
       <p>Ullamco cillum <strong><em>esse anim dolore</em></strong> duis adipisicing.</p>
       <p>Cillum incididunt <strong><em>nostrud sunt occaecat</em></strong> fugiat commodo quis in pariatur exercitation.</p>
-      <p>Veniam pariatur labore <a href="https://google.com" target="_blank">consectetur</a> laborum.</p>
+      <p>Veniam pariatur labore <a href="https://google.com" target="_blank"  rel="noopener nofollow noreferrer">consectetur</a> laborum.</p>
       <blockquote>
         <p>Fugiat consectetur culpa anim enim sit nisi culpa consequat Lorem ipsum.<br><br>Qui proident non pariatur veniam est irure.</p>
       </blockquote>

src/transformers/md2html.ts

@@ -9,6 +9,7 @@ import remarkDirectiveRehype from 'remark-directive-rehype'
 import remarkParse from 'remark-parse'
 import remarkRehype from 'remark-rehype'
 import { unified } from 'unified'
+import rehypeExternalLinks from 'rehype-external-links'
 
 import {
   rehypeRewriteOptions,
@@ -28,6 +29,7 @@ const formatter = unified()
   .use(rehypeRewrite, rehypeRewriteOptions)
   .use(rehypeRaw)
   .use(rehypeSanitize, rehypeSanitizeOptions)
+  .use(rehypeExternalLinks, { rel: ['noopener', 'nofollow', 'noreferrer'] })
   .use(rehypeFormat)
   .use(rehypeStringify, rehypeStringifyOptions)