feat(v2): add ability to set custom heading id

packages/docusaurus-mdx-loader/src/index.js

@@ -11,14 +11,14 @@ const mdx = require('@mdx-js/mdx');
 const emoji = require('remark-emoji');
 const matter = require('gray-matter');
 const stringifyObject = require('stringify-object');
-const slug = require('./remark/slug');
+const headings = require('./remark/headings');
 const toc = require('./remark/toc');
 const transformImage = require('./remark/transformImage');
 const transformLinks = require('./remark/transformLinks');
 
 const DEFAULT_OPTIONS = {
   rehypePlugins: [],
-  remarkPlugins: [emoji, slug, toc],
+  remarkPlugins: [emoji, headings, toc],
 };
 
 module.exports = async function docusaurusMdxLoader(fileString) {

packages/docusaurus-mdx-loader/src/remark/slug/__tests__/index.test.js → packages/docusaurus-mdx-loader/src/remark/headings/__tests__/index.test.js

@@ -5,13 +5,15 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-/* Based on remark-slug (https://github.com/remarkjs/remark-slug) */
+/* Based on remark-slug (https://github.com/remarkjs/remark-slug) and gatsby-remark-autolink-headers (https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-remark-autolink-headers) */
 
 /* eslint-disable no-param-reassign */
 
 import remark from 'remark';
 import u from 'unist-builder';
 import removePosition from 'unist-util-remove-position';
+import toString from 'mdast-util-to-string';
+import visit from 'unist-util-visit';
 import slug from '../index';
 
 function process(doc, plugins = []) {
@@ -27,7 +29,7 @@ function heading(label, id) {
   );
 }
 
-describe('slug plugin', () => {
+describe('headings plugin', () => {
   test('should patch `id`s and `data.hProperties.id', () => {
     const result = process('# Normal\n\n## Table of Contents\n\n# Baz\n');
     const expected = u('root', [
@@ -157,7 +159,7 @@ describe('slug plugin', () => {
     expect(result).toEqual(expected);
   });
 
-  test('should create GitHub slugs', () => {
+  test('should create GitHub-style headings ids', () => {
     const result = process(
       [
         '## I ♥ unicode',
@@ -225,7 +227,7 @@ describe('slug plugin', () => {
     expect(result).toEqual(expected);
   });
 
-  test('should generate slug from only text contents of headings if they contains HTML tags', () => {
+  test('should generate id from only text contents of headings if they contains HTML tags', () => {
     const result = process('# <span class="normal-header">Normal</span>\n');
     const expected = u('root', [
       u(
@@ -244,4 +246,58 @@ describe('slug plugin', () => {
 
     expect(result).toEqual(expected);
   });
+
+  test('should create custom headings ids', () => {
+    const result = process(`
+# Heading One {#custom_h1}
+
+## Heading Two {#custom-heading-two}
+
+# With *Bold* {#custom-withbold}
+
+# Snake-cased ID {#this_is_custom_id}
+
+# No custom ID
+
+# {#id-only}
+
+# {#text-after} custom ID
+  `);
+
+    const headers = [];
+    visit(result, 'heading', (node) => {
+      headers.push({text: toString(node), id: node.data.id});
+    });
+
+    expect(headers).toEqual([
+      {
+        id: 'custom_h1',
+        text: 'Heading One',
+      },
+      {
+        id: 'custom-heading-two',
+        text: 'Heading Two',
+      },
+      {
+        id: 'custom-withbold',
+        text: 'With Bold',
+      },
+      {
+        id: 'this_is_custom_id',
+        text: 'Snake-cased ID',
+      },
+      {
+        id: 'no-custom-id',
+        text: 'No custom I',
+      },
+      {
+        id: 'id-only',
+        text: '{#id-only}',
+      },
+      {
+        id: 'text-after-custom-id',
+        text: '{#text-after} custom ID',
+      },
+    ]);
+  });
 });

packages/docusaurus-mdx-loader/src/remark/slug/index.js → packages/docusaurus-mdx-loader/src/remark/headings/index.js

@@ -5,12 +5,14 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-/* Based on remark-slug (https://github.com/remarkjs/remark-slug) */
+/* Based on remark-slug (https://github.com/remarkjs/remark-slug) and gatsby-remark-autolink-headers (https://github.com/gatsbyjs/gatsby/blob/master/packages/gatsby-remark-autolink-headers) */
 
 const visit = require('unist-util-visit');
 const toString = require('mdast-util-to-string');
 const slugs = require('github-slugger')();
 
+const customHeadingIdRegex = /^(.*?)\s*\{#([\w-]+)\}$/;
+
 function slug() {
   const transformer = (ast) => {
     slugs.reset();
@@ -26,11 +28,29 @@ function slug() {
         const headingTextNodes = headingNode.children.filter(
           ({type}) => !['html', 'jsx'].includes(type),
         );
-        const normalizedHeadingNode =
+        const heading = toString(
           headingTextNodes.length > 0
             ? {children: headingTextNodes}
-            : headingNode;
-        id = slugs.slug(toString(normalizedHeadingNode));
+            : headingNode,
+        );
+
+        // Support explicit heading IDs
+        const customHeadingIdMatches = customHeadingIdRegex.exec(heading);
+
+        if (customHeadingIdMatches) {
+          id = customHeadingIdMatches[2];
+
+          // Remove the custom ID part from the text node
+          if (headingNode.children.length > 1) {
+            headingNode.children.pop();
+          } else {
+            const lastNode =
+              headingNode.children[headingNode.children.length - 1];
+            lastNode.value = customHeadingIdMatches[1] || heading;
+          }
+        } else {
+          id = slugs.slug(heading);
+        }
       }
 
       data.id = id;

website/docs/guides/docs/docs-create-doc.mdx

@@ -44,6 +44,10 @@ The headers are well-spaced so that the hierarchy is clear.
 - that you want your users to remember
   - and you may nest them
     - multiple times
+
+### Custom id headers {#custom-id}
+
+With `{#custom-id}` syntax you can set your own header id.
 ```
 
 This will render in the browser as follows:

website/src/pages/examples/markdownPageExample.md

@@ -119,3 +119,5 @@ import MyComponentSource from '!!raw-loader!@site/src/pages/examples/\_myCompone
 <CodeBlock className="language-jsx">{MyComponentSource}</CodeBlock>
 
 </BrowserWindow>
+
+## Custom heading id {#custom}