fix(mdx-loader): support nested admonitions #8303

packages/docusaurus-mdx-loader/src/remark/admonitions/__tests__/__fixtures__/nesting.md

@@ -0,0 +1,10 @@
+Test nested Admonitions
+
+::::info **Weather**
+On nice days, you can enjoy skiing in the mountains.
+
+:::danger *Storms*
+Take care of snowstorms...
+:::
+
+::::

packages/docusaurus-mdx-loader/src/remark/admonitions/__tests__/__snapshots__/index.test.ts.snap

@@ -42,3 +42,8 @@ exports[`admonitions remark plugin interpolation 1`] = `
 "<p>Test admonition with interpolated title/body</p>
 <admonition type="tip"><mdxAdmonitionTitle>My <code>interpolated</code> <strong>title</strong> &#x3C;button style={{color: "red"}} onClick={() => alert("click")}>test</mdxAdmonitionTitle><p><code>body</code> <strong>interpolated</strong> content</p></admonition>"
 `;
+
+exports[`admonitions remark plugin nesting 1`] = `
+"<p>Test nested Admonitions</p>
+<admonition type="info"><mdxAdmonitionTitle><strong>Weather</strong></mdxAdmonitionTitle><p>On nice days, you can enjoy skiing in the mountains.</p><admonition type="danger"><mdxAdmonitionTitle><em>Storms</em></mdxAdmonitionTitle><p>Take care of snowstorms...</p></admonition></admonition>"
+`;

packages/docusaurus-mdx-loader/src/remark/admonitions/__tests__/index.test.ts

@@ -50,4 +50,9 @@ describe('admonitions remark plugin', () => {
     const result = await processFixture('interpolation');
     expect(result).toMatchSnapshot();
   });
+
+  it('nesting', async () => {
+    const result = await processFixture('nesting');
+    expect(result).toMatchSnapshot();
+  });
 });

packages/docusaurus-mdx-loader/src/remark/admonitions/index.ts

@@ -52,9 +52,20 @@ const plugin: Plugin = function plugin(
   const options = normalizeOptions(optionsInput);
 
   const keywords = Object.values(options.keywords).map(escapeRegExp).join('|');
+  const nestingChar = escapeRegExp(options.tag.slice(0, 1));
   const tag = escapeRegExp(options.tag);
-  const regex = new RegExp(`${tag}(${keywords})(?: *(.*))?\n`);
-  const escapeTag = new RegExp(escapeRegExp(`\\${options.tag}`), 'g');
+
+  // resolve th nesting level of an opening tag
+  // ::: -> 0, :::: -> 1, ::::: -> 2 ...
+  const nestingLevelRegex = new RegExp(
+    `^${tag}(?<nestingLevel>${nestingChar}*)`,
+  );
+
+  const regex = new RegExp(`${tag}${nestingChar}*(${keywords})(?: *(.*))?\n`);
+  const escapeTag = new RegExp(
+    escapeRegExp(`\\${options.tag}${options.tag.slice(0, 1)}*`),
+    'g',
+  );
 
   // The tokenizer is called on blocks to determine if there is an admonition
   // present and create tags for it
@@ -77,6 +88,11 @@ const plugin: Plugin = function plugin(
     ];
     const food = [];
     const content = [];
+    // get the nesting level of the opening tag
+    const openingLevel =
+      nestingLevelRegex.exec(opening)!.groups!.nestingLevel!.length;
+    // used as a stack to keep track of nested admonitions
+    const nestingLevels: number[] = [openingLevel];
 
     let newValue = value;
     // consume lines until a closing tag
@@ -88,12 +104,32 @@ const plugin: Plugin = function plugin(
         next !== -1 ? newValue.slice(idx + 1, next) : newValue.slice(idx + 1);
       food.push(line);
       newValue = newValue.slice(idx + 1);
-      // the closing tag is NOT part of the content
-      if (line.startsWith(options.tag)) {
-        break;
+      const nesting = nestingLevelRegex.exec(line);
+      idx = newValue.indexOf(NEWLINE);
+      if (!nesting) {
+        content.push(line);
+        continue;
+      }
+      const tagLevel = nesting.groups!.nestingLevel!.length;
+      // first level
+      if (nestingLevels.length === 0) {
+        nestingLevels.push(tagLevel);
+        content.push(line);
+        continue;
+      }
+      const currentLevel = nestingLevels[nestingLevels.length - 1]!;
+      if (tagLevel < currentLevel) {
+        // entering a nested admonition block
+        nestingLevels.push(tagLevel);
+      } else if (tagLevel === currentLevel) {
+        // closing a nested admonition block
+        nestingLevels.pop();
+        // the closing tag is NOT part of the content
+        if (nestingLevels.length === 0) {
+          break;
+        }
       }
       content.push(line);
-      idx = newValue.indexOf(NEWLINE);
     }
 
     // consume the processed tag and replace escape sequences