Fix markdown render behaviors (#34122)HEADmain

* Fix #27645
* Add config options `MATH_CODE_BLOCK_DETECTION`, problematic syntaxes
are disabled by default
* Fix #33639
    * Add config options `RENDER_OPTIONS_*`, old behaviors are kept

4 files changed, 123 insertions, 118 deletions

diff --git a/web_src/js/markup/asciicast.ts b/web_src/js/markup/asciicast.ts
index 22dbff2d46..125bba447b 100644
--- a/web_src/js/markup/asciicast.ts
+++ b/web_src/js/markup/asciicast.ts
@@ -1,16 +1,17 @@
-export async function initMarkupRenderAsciicast(elMarkup: HTMLElement): Promise<void> {
-  const el = elMarkup.querySelector('.asciinema-player-container');
-  if (!el) return;
+import {queryElems} from '../utils/dom.ts';
 
-  const [player] = await Promise.all([
-    // @ts-expect-error: module exports no types
-    import(/* webpackChunkName: "asciinema-player" */'asciinema-player'),
-    import(/* webpackChunkName: "asciinema-player" */'asciinema-player/dist/bundle/asciinema-player.css'),
-  ]);
+export async function initMarkupRenderAsciicast(elMarkup: HTMLElement): Promise<void> {
+  queryElems(elMarkup, '.asciinema-player-container', async (el) => {
+    const [player] = await Promise.all([
+      // @ts-expect-error: module exports no types
+      import(/* webpackChunkName: "asciinema-player" */'asciinema-player'),
+      import(/* webpackChunkName: "asciinema-player" */'asciinema-player/dist/bundle/asciinema-player.css'),
+    ]);
 
-  player.create(el.getAttribute('data-asciinema-player-src'), el, {
-    // poster (a preview frame) to display until the playback is started.
-    // Set it to 1 hour (also means the end if the video is shorter) to make the preview frame show more.
-    poster: 'npt:1:0:0',
+    player.create(el.getAttribute('data-asciinema-player-src'), el, {
+      // poster (a preview frame) to display until the playback is started.
+      // Set it to 1 hour (also means the end if the video is shorter) to make the preview frame show more.
+      poster: 'npt:1:0:0',
+    });
   });
 }
diff --git a/web_src/js/markup/codecopy.ts b/web_src/js/markup/codecopy.ts
index 4430256848..67284bad55 100644
--- a/web_src/js/markup/codecopy.ts
+++ b/web_src/js/markup/codecopy.ts
@@ -1,4 +1,5 @@
 import {svg} from '../svg.ts';
+import {queryElems} from '../utils/dom.ts';
 
 export function makeCodeCopyButton(): HTMLButtonElement {
   const button = document.createElement('button');
@@ -8,11 +9,12 @@ export function makeCodeCopyButton(): HTMLButtonElement {
 }
 
 export function initMarkupCodeCopy(elMarkup: HTMLElement): void {
-  const el = elMarkup.querySelector('.code-block code'); // .markup .code-block code
-  if (!el || !el.textContent) return;
-
-  const btn = makeCodeCopyButton();
-  // remove final trailing newline introduced during HTML rendering
-  btn.setAttribute('data-clipboard-text', el.textContent.replace(/\r?\n$/, ''));
-  el.after(btn);
+  // .markup .code-block code
+  queryElems(elMarkup, '.code-block code', (el) => {
+    if (!el.textContent) return;
+    const btn = makeCodeCopyButton();
+    // remove final trailing newline introduced during HTML rendering
+    btn.setAttribute('data-clipboard-text', el.textContent.replace(/\r?\n$/, ''));
+    el.after(btn);
+  });
 }
diff --git a/web_src/js/markup/math.ts b/web_src/js/markup/math.ts
index 2a4468bf2e..bc118137a1 100644
--- a/web_src/js/markup/math.ts
+++ b/web_src/js/markup/math.ts
@@ -1,4 +1,5 @@
 import {displayError} from './common.ts';
+import {queryElems} from '../utils/dom.ts';
 
 function targetElement(el: Element): {target: Element, displayAsBlock: boolean} {
   // The target element is either the parent "code block with loading indicator", or itself
@@ -12,35 +13,35 @@ function targetElement(el: Element): {target: Element, displayAsBlock: boolean}
 }
 
 export async function initMarkupCodeMath(elMarkup: HTMLElement): Promise<void> {
-  const el = elMarkup.querySelector('code.language-math'); // .markup code.language-math'
-  if (!el) return;
+  // .markup code.language-math'
+  queryElems(elMarkup, 'code.language-math', async (el) => {
+    const [{default: katex}] = await Promise.all([
+      import(/* webpackChunkName: "katex" */'katex'),
+      import(/* webpackChunkName: "katex" */'katex/dist/katex.css'),
+    ]);
 
-  const [{default: katex}] = await Promise.all([
-    import(/* webpackChunkName: "katex" */'katex'),
-    import(/* webpackChunkName: "katex" */'katex/dist/katex.css'),
-  ]);
+    const MAX_CHARS = 1000;
+    const MAX_SIZE = 25;
+    const MAX_EXPAND = 1000;
 
-  const MAX_CHARS = 1000;
-  const MAX_SIZE = 25;
-  const MAX_EXPAND = 1000;
+    const {target, displayAsBlock} = targetElement(el);
+    if (target.hasAttribute('data-render-done')) return;
+    const source = el.textContent;
 
-  const {target, displayAsBlock} = targetElement(el);
-  if (target.hasAttribute('data-render-done')) return;
-  const source = el.textContent;
-
-  if (source.length > MAX_CHARS) {
-    displayError(target, new Error(`Math source of ${source.length} characters exceeds the maximum allowed length of ${MAX_CHARS}.`));
-    return;
-  }
-  try {
-    const tempEl = document.createElement(displayAsBlock ? 'p' : 'span');
-    katex.render(source, tempEl, {
-      maxSize: MAX_SIZE,
-      maxExpand: MAX_EXPAND,
-      displayMode: displayAsBlock, // katex: true for display (block) mode, false for inline mode
-    });
-    target.replaceWith(tempEl);
-  } catch (error) {
-    displayError(target, error);
-  }
+    if (source.length > MAX_CHARS) {
+      displayError(target, new Error(`Math source of ${source.length} characters exceeds the maximum allowed length of ${MAX_CHARS}.`));
+      return;
+    }
+    try {
+      const tempEl = document.createElement(displayAsBlock ? 'p' : 'span');
+      katex.render(source, tempEl, {
+        maxSize: MAX_SIZE,
+        maxExpand: MAX_EXPAND,
+        displayMode: displayAsBlock, // katex: true for display (block) mode, false for inline mode
+      });
+      target.replaceWith(tempEl);
+    } catch (error) {
+      displayError(target, error);
+    }
+  });
 }
diff --git a/web_src/js/markup/mermaid.ts b/web_src/js/markup/mermaid.ts
index b4bf3153ea..ac24b3bcba 100644
--- a/web_src/js/markup/mermaid.ts
+++ b/web_src/js/markup/mermaid.ts
@@ -1,6 +1,7 @@
 import {isDarkTheme} from '../utils.ts';
 import {makeCodeCopyButton} from './codecopy.ts';
 import {displayError} from './common.ts';
+import {queryElems} from '../utils/dom.ts';
 
 const {mermaidMaxSourceCharacters} = window.config;
 
@@ -11,77 +12,77 @@ body {margin: 0; padding: 0; overflow: hidden}
 blockquote, dd, dl, figure, h1, h2, h3, h4, h5, h6, hr, p, pre {margin: 0}`;
 
 export async function initMarkupCodeMermaid(elMarkup: HTMLElement): Promise<void> {
-  const el = elMarkup.querySelector('code.language-mermaid'); // .markup code.language-mermaid
-  if (!el) return;
-
-  const {default: mermaid} = await import(/* webpackChunkName: "mermaid" */'mermaid');
-
-  mermaid.initialize({
-    startOnLoad: false,
-    theme: isDarkTheme() ? 'dark' : 'neutral',
-    securityLevel: 'strict',
-    suppressErrorRendering: true,
-  });
-
-  const pre = el.closest('pre');
-  if (pre.hasAttribute('data-render-done')) return;
-
-  const source = el.textContent;
-  if (mermaidMaxSourceCharacters >= 0 && source.length > mermaidMaxSourceCharacters) {
-    displayError(pre, new Error(`Mermaid source of ${source.length} characters exceeds the maximum allowed length of ${mermaidMaxSourceCharacters}.`));
-    return;
-  }
-
-  try {
-    await mermaid.parse(source);
-  } catch (err) {
-    displayError(pre, err);
-    return;
-  }
-
-  try {
-    // can't use bindFunctions here because we can't cross the iframe boundary. This
-    // means js-based interactions won't work but they aren't intended to work either
-    const {svg} = await mermaid.render('mermaid', source);
-
-    const iframe = document.createElement('iframe');
-    iframe.classList.add('markup-content-iframe', 'tw-invisible');
-    iframe.srcdoc = `<html><head><style>${iframeCss}</style></head><body>${svg}</body></html>`;
-
-    const mermaidBlock = document.createElement('div');
-    mermaidBlock.classList.add('mermaid-block', 'is-loading', 'tw-hidden');
-    mermaidBlock.append(iframe);
-
-    const btn = makeCodeCopyButton();
-    btn.setAttribute('data-clipboard-text', source);
-    mermaidBlock.append(btn);
-
-    const updateIframeHeight = () => {
-      const body = iframe.contentWindow?.document?.body;
-      if (body) {
-        iframe.style.height = `${body.clientHeight}px`;
-      }
-    };
-
-    iframe.addEventListener('load', () => {
-      pre.replaceWith(mermaidBlock);
-      mermaidBlock.classList.remove('tw-hidden');
-      updateIframeHeight();
-      setTimeout(() => { // avoid flash of iframe background
-        mermaidBlock.classList.remove('is-loading');
-        iframe.classList.remove('tw-invisible');
-      }, 0);
-
-      // update height when element's visibility state changes, for example when the diagram is inside
-      // a <details> + <summary> block and the <details> block becomes visible upon user interaction, it
-      // would initially set a incorrect height and the correct height is set during this callback.
-      (new IntersectionObserver(() => {
-        updateIframeHeight();
-      }, {root: document.documentElement})).observe(iframe);
+  // .markup code.language-mermaid
+  queryElems(elMarkup, 'code.language-mermaid', async (el) => {
+    const {default: mermaid} = await import(/* webpackChunkName: "mermaid" */'mermaid');
+
+    mermaid.initialize({
+      startOnLoad: false,
+      theme: isDarkTheme() ? 'dark' : 'neutral',
+      securityLevel: 'strict',
+      suppressErrorRendering: true,
     });
 
-    document.body.append(mermaidBlock);
-  } catch (err) {
-    displayError(pre, err);
-  }
+    const pre = el.closest('pre');
+    if (pre.hasAttribute('data-render-done')) return;
+
+    const source = el.textContent;
+    if (mermaidMaxSourceCharacters >= 0 && source.length > mermaidMaxSourceCharacters) {
+      displayError(pre, new Error(`Mermaid source of ${source.length} characters exceeds the maximum allowed length of ${mermaidMaxSourceCharacters}.`));
+      return;
+    }
+
+    try {
+      await mermaid.parse(source);
+    } catch (err) {
+      displayError(pre, err);
+      return;
+    }
+
+    try {
+      // can't use bindFunctions here because we can't cross the iframe boundary. This
+      // means js-based interactions won't work but they aren't intended to work either
+      const {svg} = await mermaid.render('mermaid', source);
+
+      const iframe = document.createElement('iframe');
+      iframe.classList.add('markup-content-iframe', 'tw-invisible');
+      iframe.srcdoc = `<html><head><style>${iframeCss}</style></head><body>${svg}</body></html>`;
+
+      const mermaidBlock = document.createElement('div');
+      mermaidBlock.classList.add('mermaid-block', 'is-loading', 'tw-hidden');
+      mermaidBlock.append(iframe);
+
+      const btn = makeCodeCopyButton();
+      btn.setAttribute('data-clipboard-text', source);
+      mermaidBlock.append(btn);
+
+      const updateIframeHeight = () => {
+        const body = iframe.contentWindow?.document?.body;
+        if (body) {
+          iframe.style.height = `${body.clientHeight}px`;
+        }
+      };
+
+      iframe.addEventListener('load', () => {
+        pre.replaceWith(mermaidBlock);
+        mermaidBlock.classList.remove('tw-hidden');
+        updateIframeHeight();
+        setTimeout(() => { // avoid flash of iframe background
+          mermaidBlock.classList.remove('is-loading');
+          iframe.classList.remove('tw-invisible');
+        }, 0);
+
+        // update height when element's visibility state changes, for example when the diagram is inside
+        // a <details> + <summary> block and the <details> block becomes visible upon user interaction, it
+        // would initially set a incorrect height and the correct height is set during this callback.
+        (new IntersectionObserver(() => {
+          updateIframeHeight();
+        }, {root: document.documentElement})).observe(iframe);
+      });
+
+      document.body.append(mermaidBlock);
+    } catch (err) {
+      displayError(pre, err);
+    }
+  });
 }