test: add milkdown markdown roundtrip integration coverage

Co-authored-by: rfc1437 <774975+rfc1437@users.noreply.github.com>

src/renderer/components/MilkdownEditor/MilkdownEditor.tsx

@@ -22,7 +22,7 @@ import { imageResolverPlugin } from '../../plugins/imageResolverPlugin';
 import '../../macros';
 import './MilkdownEditor.css';
 import { InsertModal } from '../InsertModal';
-import { unescapeMacroSyntax } from '../../utils/markdownEscape';
+import { normalizeMilkdownMarkdown } from '../../utils/markdownEscape';
 
 // Remark plugin to force tight lists (no blank lines between list items)
 const remarkTightListsPlugin: Plugin<[Record<string, unknown>], Root> = () => {
@@ -68,11 +68,11 @@ export const shouldPropagateMilkdownChange = ({
   externalContent,
   hasUserInteracted,
 }: MilkdownChangePropagationInput): boolean => {
-  const unescaped = unescapeMacroSyntax(markdown);
-  const prevUnescaped = unescapeMacroSyntax(prevMarkdown);
-  const externalUnescaped = unescapeMacroSyntax(externalContent);
+  const normalized = normalizeMilkdownMarkdown(markdown);
+  const prevNormalized = normalizeMilkdownMarkdown(prevMarkdown);
+  const externalNormalized = normalizeMilkdownMarkdown(externalContent);
 
-  if (unescaped === prevUnescaped) {
+  if (normalized === prevNormalized) {
     return false;
   }
 
@@ -80,7 +80,7 @@ export const shouldPropagateMilkdownChange = ({
     return false;
   }
 
-  return unescaped !== externalUnescaped;
+  return normalized !== externalNormalized;
 };
 
 interface EditorToolbarProps {
@@ -329,7 +329,7 @@ const MilkdownProviderInner: React.FC<MilkdownEditorProps> = ({
 
           if (shouldEmit) {
             isInternalChange.current = true;
-            onChangeRef.current(unescapeMacroSyntax(markdown));
+            onChangeRef.current(normalizeMilkdownMarkdown(markdown));
           }
         });
       })

src/renderer/utils/markdownEscape.ts

@@ -37,3 +37,37 @@ export function unescapeMacroSyntax(markdown: string): string {
   
   return result;
 }
+
+const unorderedListItemPattern = /^\s{0,3}[-+*]\s/;
+const orderedListItemPattern = /^\s{0,3}\d+\.\s/;
+
+function getListLineType(line: string): 'ordered' | 'unordered' | null {
+  if (unorderedListItemPattern.test(line)) return 'unordered';
+  if (orderedListItemPattern.test(line)) return 'ordered';
+  return null;
+}
+
+export function normalizeMilkdownMarkdown(markdown: string): string {
+  const unescaped = unescapeMacroSyntax(markdown);
+  const lines = unescaped.split('\n');
+  const normalized: string[] = [];
+
+  for (let i = 0; i < lines.length; i += 1) {
+    const line = lines[i];
+
+    const previousListType = i > 0 ? getListLineType(lines[i - 1]) : null;
+    const nextListType = i < lines.length - 1 ? getListLineType(lines[i + 1]) : null;
+    if (line === '' && previousListType !== null && previousListType === nextListType) {
+      continue;
+    }
+
+    if (line === '>') {
+      normalized.push('> ');
+      continue;
+    }
+
+    normalized.push(line);
+  }
+
+  return normalized.join('\n');
+}

tests/renderer/components/MilkdownEditor.test.ts

@@ -45,4 +45,15 @@ describe('shouldPropagateMilkdownChange', () => {
 
     expect(result).toBe(false);
   });
+
+  it('does not propagate list-spacing-only normalization differences', () => {
+    const result = shouldPropagateMilkdownChange({
+      markdown: '- one\n\n- two',
+      prevMarkdown: '',
+      externalContent: '- one\n- two',
+      hasUserInteracted: true,
+    });
+
+    expect(result).toBe(false);
+  });
 });

tests/renderer/components/MilkdownMarkdownRoundTrip.test.ts

@@ -0,0 +1,74 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import * as fs from 'fs';
+import * as path from 'path';
+import matter from 'gray-matter';
+import { Editor, defaultValueCtx, parserCtx, remarkPluginsCtx, remarkStringifyOptionsCtx, rootCtx, serializerCtx } from '@milkdown/kit/core';
+import { commonmark } from '@milkdown/kit/preset/commonmark';
+import { gfm } from '@milkdown/kit/preset/gfm';
+import type { Plugin } from 'unified';
+import type { Root, List, ListItem } from 'mdast';
+import { visit } from 'unist-util-visit';
+import { normalizeMilkdownMarkdown } from '../../../src/renderer/utils/markdownEscape';
+
+const wxrRefDir = '/home/runner/work/bDS/bDS/tests/assets/wxr-ref';
+
+const remarkTightListsPlugin: Plugin<[Record<string, unknown>], Root> = () => {
+  return (tree: Root) => {
+    visit(tree, 'list', (node) => {
+      const listNode = node as List;
+      listNode.spread = false;
+      for (const child of listNode.children) {
+        if (child.type === 'listItem') {
+          (child as ListItem).spread = false;
+        }
+      }
+    });
+  };
+};
+
+describe('Milkdown markdown round trip', () => {
+  let root: HTMLDivElement;
+
+  beforeEach(() => {
+    root = document.createElement('div');
+    document.body.appendChild(root);
+  });
+
+  afterEach(() => {
+    root.remove();
+  });
+
+  it('preserves reference markdown bodies across load -> internal -> markdown cycle', async () => {
+    const files = fs.readdirSync(wxrRefDir).filter((file) => file.endsWith('.md'));
+
+    for (const file of files) {
+      const raw = fs.readFileSync(path.join(wxrRefDir, file), 'utf-8');
+      const { content } = matter(raw);
+
+      const editor = await Editor.make()
+        .config((ctx) => {
+          ctx.set(rootCtx, root);
+          ctx.set(defaultValueCtx, content);
+          ctx.set(remarkStringifyOptionsCtx, {
+            bullet: '-',
+            listItemIndent: 'one',
+          });
+          ctx.set(remarkPluginsCtx, [{ plugin: remarkTightListsPlugin, options: {} }]);
+        })
+        .use(commonmark)
+        .use(gfm)
+        .create();
+
+      const serialized = editor.action((ctx) => {
+        const parser = ctx.get(parserCtx);
+        const serializer = ctx.get(serializerCtx);
+        const doc = parser(content);
+        return normalizeMilkdownMarkdown(serializer(doc));
+      });
+
+      await editor.destroy();
+
+      expect(serialized, `round trip mismatch for ${file}`).toBe(content);
+    }
+  }, 30000);
+});