test: add milkdown markdown roundtrip integration coverage

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

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);
+});