1 files changed, 171 insertions, 3 deletions

diff --git a/app/assets/javascripts/content_editor/services/markdown_serializer.js b/app/assets/javascripts/content_editor/services/markdown_serializer.js
index f121cc9affd..df4d31c3d7f 100644
--- a/app/assets/javascripts/content_editor/services/markdown_serializer.js
+++ b/app/assets/javascripts/content_editor/services/markdown_serializer.js
@@ -1,5 +1,165 @@
-import { MarkdownSerializer as ProseMirrorMarkdownSerializer } from 'prosemirror-markdown/src/to_markdown';
+import {
+  MarkdownSerializer as ProseMirrorMarkdownSerializer,
+  defaultMarkdownSerializer,
+} from 'prosemirror-markdown/src/to_markdown';
 import { DOMParser as ProseMirrorDOMParser } from 'prosemirror-model';
+import Blockquote from '../extensions/blockquote';
+import Bold from '../extensions/bold';
+import BulletList from '../extensions/bullet_list';
+import Code from '../extensions/code';
+import CodeBlockHighlight from '../extensions/code_block_highlight';
+import Emoji from '../extensions/emoji';
+import HardBreak from '../extensions/hard_break';
+import Heading from '../extensions/heading';
+import HorizontalRule from '../extensions/horizontal_rule';
+import Image from '../extensions/image';
+import InlineDiff from '../extensions/inline_diff';
+import Italic from '../extensions/italic';
+import Link from '../extensions/link';
+import ListItem from '../extensions/list_item';
+import OrderedList from '../extensions/ordered_list';
+import Paragraph from '../extensions/paragraph';
+import Reference from '../extensions/reference';
+import Strike from '../extensions/strike';
+import Subscript from '../extensions/subscript';
+import Superscript from '../extensions/superscript';
+import Table from '../extensions/table';
+import TableCell from '../extensions/table_cell';
+import TableHeader from '../extensions/table_header';
+import TableRow from '../extensions/table_row';
+import TaskItem from '../extensions/task_item';
+import TaskList from '../extensions/task_list';
+import Text from '../extensions/text';
+
+const defaultSerializerConfig = {
+  marks: {
+    [Bold.name]: defaultMarkdownSerializer.marks.strong,
+    [Code.name]: defaultMarkdownSerializer.marks.code,
+    [Italic.name]: { open: '_', close: '_', mixable: true, expelEnclosingWhitespace: true },
+    [Subscript.name]: { open: '<sub>', close: '</sub>', mixable: true },
+    [Superscript.name]: { open: '<sup>', close: '</sup>', mixable: true },
+    [InlineDiff.name]: {
+      mixable: true,
+      open(state, mark) {
+        return mark.attrs.type === 'addition' ? '{+' : '{-';
+      },
+      close(state, mark) {
+        return mark.attrs.type === 'addition' ? '+}' : '-}';
+      },
+    },
+    [Link.name]: {
+      open() {
+        return '[';
+      },
+      close(state, mark) {
+        const href = mark.attrs.canonicalSrc || mark.attrs.href;
+        return `](${state.esc(href)}${
+          mark.attrs.title ? ` ${state.quote(mark.attrs.title)}` : ''
+        })`;
+      },
+    },
+    [Strike.name]: {
+      open: '~~',
+      close: '~~',
+      mixable: true,
+      expelEnclosingWhitespace: true,
+    },
+  },
+  nodes: {
+    [Blockquote.name]: defaultMarkdownSerializer.nodes.blockquote,
+    [BulletList.name]: defaultMarkdownSerializer.nodes.bullet_list,
+    [CodeBlockHighlight.name]: (state, node) => {
+      state.write(`\`\`\`${node.attrs.language || ''}\n`);
+      state.text(node.textContent, false);
+      state.ensureNewLine();
+      state.write('```');
+      state.closeBlock(node);
+    },
+    [Emoji.name]: (state, node) => {
+      const { name } = node.attrs;
+
+      state.write(`:${name}:`);
+    },
+    [HardBreak.name]: defaultMarkdownSerializer.nodes.hard_break,
+    [Heading.name]: defaultMarkdownSerializer.nodes.heading,
+    [HorizontalRule.name]: defaultMarkdownSerializer.nodes.horizontal_rule,
+    [Image.name]: (state, node) => {
+      const { alt, canonicalSrc, src, title } = node.attrs;
+      const quotedTitle = title ? ` ${state.quote(title)}` : '';
+
+      state.write(`![${state.esc(alt || '')}](${state.esc(canonicalSrc || src)}${quotedTitle})`);
+    },
+    [ListItem.name]: defaultMarkdownSerializer.nodes.list_item,
+    [OrderedList.name]: defaultMarkdownSerializer.nodes.ordered_list,
+    [Paragraph.name]: defaultMarkdownSerializer.nodes.paragraph,
+    [Reference.name]: (state, node) => {
+      state.write(node.attrs.originalText || node.attrs.text);
+    },
+    [Table.name]: (state, node) => {
+      state.renderContent(node);
+    },
+    [TableCell.name]: (state, node) => {
+      state.renderInline(node);
+    },
+    [TableHeader.name]: (state, node) => {
+      state.renderInline(node);
+    },
+    [TableRow.name]: (state, node) => {
+      const isHeaderRow = node.child(0).type.name === 'tableHeader';
+
+      const renderRow = () => {
+        const cellWidths = [];
+
+        state.flushClose(1);
+
+        state.write('| ');
+        node.forEach((cell, _, i) => {
+          if (i) state.write(' | ');
+
+          const { length } = state.out;
+          state.render(cell, node, i);
+          cellWidths.push(state.out.length - length);
+        });
+        state.write(' |');
+
+        state.closeBlock(node);
+
+        return cellWidths;
+      };
+
+      const renderHeaderRow = (cellWidths) => {
+        state.flushClose(1);
+
+        state.write('|');
+        node.forEach((cell, _, i) => {
+          if (i) state.write('|');
+
+          state.write(cell.attrs.align === 'center' ? ':' : '-');
+          state.write(state.repeat('-', cellWidths[i]));
+          state.write(cell.attrs.align === 'center' || cell.attrs.align === 'right' ? ':' : '-');
+        });
+        state.write('|');
+
+        state.closeBlock(node);
+      };
+
+      if (isHeaderRow) {
+        renderHeaderRow(renderRow());
+      } else {
+        renderRow();
+      }
+    },
+    [TaskItem.name]: (state, node) => {
+      state.write(`[${node.attrs.checked ? 'x' : ' '}] `);
+      state.renderContent(node);
+    },
+    [TaskList.name]: (state, node) => {
+      if (node.attrs.type === 'ul') defaultMarkdownSerializer.nodes.bullet_list(state, node);
+      else defaultMarkdownSerializer.nodes.ordered_list(state, node);
+    },
+    [Text.name]: defaultMarkdownSerializer.nodes.text,
+  },
+};
 
 const wrapHtmlPayload = (payload) => `<div>${payload}</div>`;
 
@@ -50,8 +210,16 @@ export default ({ render = () => null, serializerConfig }) => ({
    */
   serialize: ({ schema, content }) => {
     const proseMirrorDocument = schema.nodeFromJSON(content);
-    const { nodes, marks } = serializerConfig;
-    const serializer = new ProseMirrorMarkdownSerializer(nodes, marks);
+    const serializer = new ProseMirrorMarkdownSerializer(
+      {
+        ...defaultSerializerConfig.nodes,
+        ...serializerConfig.nodes,
+      },
+      {
+        ...defaultSerializerConfig.marks,
+        ...serializerConfig.marks,
+      },
+    );
 
     return serializer.serialize(proseMirrorDocument, {
       tightLists: true,