Support quote selected comments to reply (#32431)

Many existing tests were quite hacky, these could be improved later.

<details>

![image](https://github.com/user-attachments/assets/93aebb4f-9de5-4cb8-910b-50c64cbcd25a)

</details>

web_src/js/features/repo-issue-edit.ts

@@ -1,4 +1,3 @@
-import $ from 'jquery';
 import {handleReply} from './repo-issue.ts';
 import {getComboMarkdownEditor, initComboMarkdownEditor, ComboMarkdownEditor} from './comp/ComboMarkdownEditor.ts';
 import {POST} from '../modules/fetch.ts';
@@ -7,11 +6,14 @@ import {hideElem, querySingleVisibleElem, showElem} from '../utils/dom.ts';
 import {attachRefIssueContextPopup} from './contextpopup.ts';
 import {initCommentContent, initMarkupContent} from '../markup/content.ts';
 import {triggerUploadStateChanged} from './comp/EditorUpload.ts';
+import {convertHtmlToMarkdown} from '../markup/html2markdown.ts';
 
-async function onEditContent(event) {
-  event.preventDefault();
+async function tryOnEditContent(e) {
+  const clickTarget = e.target.closest('.edit-content');
+  if (!clickTarget) return;
 
-  const segment = this.closest('.header').nextElementSibling;
+  e.preventDefault();
+  const segment = clickTarget.closest('.header').nextElementSibling;
   const editContentZone = segment.querySelector('.edit-content-zone');
   const renderContent = segment.querySelector('.render-content');
   const rawContent = segment.querySelector('.raw-content');
@@ -102,33 +104,53 @@ async function onEditContent(event) {
   triggerUploadStateChanged(comboMarkdownEditor.container);
 }
 
+function extractSelectedMarkdown(container: HTMLElement) {
+  const selection = window.getSelection();
+  if (!selection.rangeCount) return '';
+  const range = selection.getRangeAt(0);
+  if (!container.contains(range.commonAncestorContainer)) return '';
+
+  // todo: if commonAncestorContainer parent has "[data-markdown-original-content]" attribute, use the parent's markdown content
+  // otherwise, use the selected HTML content and respect all "[data-markdown-original-content]/[data-markdown-generated-content]" attributes
+  const contents = selection.getRangeAt(0).cloneContents();
+  const el = document.createElement('div');
+  el.append(contents);
+  return convertHtmlToMarkdown(el);
+}
+
+async function tryOnQuoteReply(e) {
+  const clickTarget = (e.target as HTMLElement).closest('.quote-reply');
+  if (!clickTarget) return;
+
+  e.preventDefault();
+  const contentToQuoteId = clickTarget.getAttribute('data-target');
+  const targetRawToQuote = document.querySelector<HTMLElement>(`#${contentToQuoteId}.raw-content`);
+  const targetMarkupToQuote = targetRawToQuote.parentElement.querySelector<HTMLElement>('.render-content.markup');
+  let contentToQuote = extractSelectedMarkdown(targetMarkupToQuote);
+  if (!contentToQuote) contentToQuote = targetRawToQuote.textContent;
+  const quotedContent = `${contentToQuote.replace(/^/mg, '> ')}\n`;
+
+  let editor;
+  if (clickTarget.classList.contains('quote-reply-diff')) {
+    const replyBtn = clickTarget.closest('.comment-code-cloud').querySelector('button.comment-form-reply');
+    editor = await handleReply(replyBtn);
+  } else {
+    // for normal issue/comment page
+    editor = getComboMarkdownEditor(document.querySelector('#comment-form .combo-markdown-editor'));
+  }
+
+  if (editor.value()) {
+    editor.value(`${editor.value()}\n\n${quotedContent}`);
+  } else {
+    editor.value(quotedContent);
+  }
+  editor.focus();
+  editor.moveCursorToEnd();
+}
+
 export function initRepoIssueCommentEdit() {
-  // Edit issue or comment content
-  $(document).on('click', '.edit-content', onEditContent);
-
-  // Quote reply
-  $(document).on('click', '.quote-reply', async function (event) {
-    event.preventDefault();
-    const target = this.getAttribute('data-target');
-    const quote = document.querySelector(`#${target}`).textContent.replace(/\n/g, '\n> ');
-    const content = `> ${quote}\n\n`;
-
-    let editor;
-    if (this.classList.contains('quote-reply-diff')) {
-      const replyBtn = this.closest('.comment-code-cloud').querySelector('button.comment-form-reply');
-      editor = await handleReply(replyBtn);
-    } else {
-      // for normal issue/comment page
-      editor = getComboMarkdownEditor($('#comment-form .combo-markdown-editor'));
-    }
-    if (editor) {
-      if (editor.value()) {
-        editor.value(`${editor.value()}\n\n${content}`);
-      } else {
-        editor.value(content);
-      }
-      editor.focus();
-      editor.moveCursorToEnd();
-    }
+  document.addEventListener('click', (e) => {
+    tryOnEditContent(e); // Edit issue or comment content
+    tryOnQuoteReply(e); // Quote reply to the comment editor
   });
 }

web_src/js/markup/html2markdown.test.ts

@@ -0,0 +1,24 @@
+import {convertHtmlToMarkdown} from './html2markdown.ts';
+import {createElementFromHTML} from '../utils/dom.ts';
+
+const h = createElementFromHTML;
+
+test('convertHtmlToMarkdown', () => {
+  expect(convertHtmlToMarkdown(h(`<h1>h</h1>`))).toBe('# h');
+  expect(convertHtmlToMarkdown(h(`<strong>txt</strong>`))).toBe('**txt**');
+  expect(convertHtmlToMarkdown(h(`<em>txt</em>`))).toBe('_txt_');
+  expect(convertHtmlToMarkdown(h(`<del>txt</del>`))).toBe('~~txt~~');
+
+  expect(convertHtmlToMarkdown(h(`<a href="link">txt</a>`))).toBe('[txt](link)');
+  expect(convertHtmlToMarkdown(h(`<a href="https://link">https://link</a>`))).toBe('https://link');
+
+  expect(convertHtmlToMarkdown(h(`<img src="link">`))).toBe('![image](link)');
+  expect(convertHtmlToMarkdown(h(`<img src="link" alt="name">`))).toBe('![name](link)');
+  expect(convertHtmlToMarkdown(h(`<img src="link" width="1" height="1">`))).toBe('<img alt="image" width="1" height="1" src="link">');
+
+  expect(convertHtmlToMarkdown(h(`<p>txt</p>`))).toBe('txt\n');
+  expect(convertHtmlToMarkdown(h(`<blockquote>a\nb</blockquote>`))).toBe('> a\n> b\n');
+
+  expect(convertHtmlToMarkdown(h(`<ol><li>a<ul><li>b</li></ul></li></ol>`))).toBe('1. a\n    * b\n\n');
+  expect(convertHtmlToMarkdown(h(`<ol><li><input checked>a</li></ol>`))).toBe('1. [x] a\n');
+});

web_src/js/markup/html2markdown.ts

@@ -0,0 +1,119 @@
+import {htmlEscape} from 'escape-goat';
+
+type Processors = {
+  [tagName: string]: (el: HTMLElement) => string | HTMLElement | void;
+}
+
+type ProcessorContext = {
+  elementIsFirst: boolean;
+  elementIsLast: boolean;
+  listNestingLevel: number;
+}
+
+function prepareProcessors(ctx:ProcessorContext): Processors {
+  const processors = {
+    H1(el) {
+      const level = parseInt(el.tagName.slice(1));
+      el.textContent = `${'#'.repeat(level)} ${el.textContent.trim()}`;
+    },
+    STRONG(el) {
+      return `**${el.textContent}**`;
+    },
+    EM(el) {
+      return `_${el.textContent}_`;
+    },
+    DEL(el) {
+      return `~~${el.textContent}~~`;
+    },
+
+    A(el) {
+      const text = el.textContent || 'link';
+      const href = el.getAttribute('href');
+      if (/^https?:/.test(text) && text === href) {
+        return text;
+      }
+      return href ? `[${text}](${href})` : text;
+    },
+    IMG(el) {
+      const alt = el.getAttribute('alt') || 'image';
+      const src = el.getAttribute('src');
+      const widthAttr = el.hasAttribute('width') ? ` width="${htmlEscape(el.getAttribute('width') || '')}"` : '';
+      const heightAttr = el.hasAttribute('height') ? ` height="${htmlEscape(el.getAttribute('height') || '')}"` : '';
+      if (widthAttr || heightAttr) {
+        return `<img alt="${htmlEscape(alt)}"${widthAttr}${heightAttr} src="${htmlEscape(src)}">`;
+      }
+      return `![${alt}](${src})`;
+    },
+
+    P(el) {
+      el.textContent = `${el.textContent}\n`;
+    },
+    BLOCKQUOTE(el) {
+      el.textContent = `${el.textContent.replace(/^/mg, '> ')}\n`;
+    },
+
+    OL(el) {
+      const preNewLine = ctx.listNestingLevel ? '\n' : '';
+      el.textContent = `${preNewLine}${el.textContent}\n`;
+    },
+    LI(el) {
+      const parent = el.parentNode;
+      const bullet = parent.tagName === 'OL' ? `1. ` : '* ';
+      const nestingIdentLevel = Math.max(0, ctx.listNestingLevel - 1);
+      el.textContent = `${' '.repeat(nestingIdentLevel * 4)}${bullet}${el.textContent}${ctx.elementIsLast ? '' : '\n'}`;
+      return el;
+    },
+    INPUT(el) {
+      return el.checked ? '[x] ' : '[ ] ';
+    },
+
+    CODE(el) {
+      const text = el.textContent;
+      if (el.parentNode && el.parentNode.tagName === 'PRE') {
+        el.textContent = `\`\`\`\n${text}\n\`\`\`\n`;
+        return el;
+      }
+      if (text.includes('`')) {
+        return `\`\` ${text} \`\``;
+      }
+      return `\`${text}\``;
+    },
+  };
+  processors['UL'] = processors.OL;
+  for (let level = 2; level <= 6; level++) {
+    processors[`H${level}`] = processors.H1;
+  }
+  return processors;
+}
+
+function processElement(ctx :ProcessorContext, processors: Processors, el: HTMLElement) {
+  if (el.hasAttribute('data-markdown-generated-content')) return el.textContent;
+  if (el.tagName === 'A' && el.children.length === 1 && el.children[0].tagName === 'IMG') {
+    return processElement(ctx, processors, el.children[0] as HTMLElement);
+  }
+
+  const isListContainer = el.tagName === 'OL' || el.tagName === 'UL';
+  if (isListContainer) ctx.listNestingLevel++;
+  for (let i = 0; i < el.children.length; i++) {
+    ctx.elementIsFirst = i === 0;
+    ctx.elementIsLast = i === el.children.length - 1;
+    processElement(ctx, processors, el.children[i] as HTMLElement);
+  }
+  if (isListContainer) ctx.listNestingLevel--;
+
+  if (processors[el.tagName]) {
+    const ret = processors[el.tagName](el);
+    if (ret && ret !== el) {
+      el.replaceWith(typeof ret === 'string' ? document.createTextNode(ret) : ret);
+    }
+  }
+}
+
+export function convertHtmlToMarkdown(el: HTMLElement): string {
+  const div = document.createElement('div');
+  div.append(el);
+  const ctx = {} as ProcessorContext;
+  ctx.listNestingLevel = 0;
+  processElement(ctx, prepareProcessors(ctx), el);
+  return div.textContent;
+}