Fix Markdown mark round-trips (#219)

tests/markdown-roundtrip.test.mjs

@@ -0,0 +1,118 @@
+import assert from 'node:assert/strict';
+import { readFile } from 'node:fs/promises';
+import test from 'node:test';
+import MarkdownIt from 'markdown-it';
+import { Schema } from '@tiptap/pm/model';
+import { transformWithEsbuild } from 'vite';
+
+const source = await readFile(
+  new URL('../src/lib/editor/markdown.ts', import.meta.url),
+  'utf8'
+);
+const { code } = await transformWithEsbuild(source, 'markdown.ts', {
+  loader: 'ts',
+  format: 'esm',
+  target: 'esnext'
+});
+const { serializeInlineMarkdown } = await import(
+  `data:text/javascript;base64,${Buffer.from(code).toString('base64')}`
+);
+
+// Link intentionally precedes formatting marks in the schema. This matches the
+// mark order produced by the app and reproduces the original per-text-node bug.
+const schema = new Schema({
+  nodes: {
+    doc: { content: 'block+' },
+    paragraph: { content: 'text*', group: 'block' },
+    text: { group: 'inline' }
+  },
+  marks: {
+    link: { attrs: { href: {} } },
+    bold: {},
+    italic: {},
+    wikiLink: {
+      attrs: {
+        title: { default: null },
+        aliased: { default: false }
+      }
+    }
+  }
+});
+
+const markdown = new MarkdownIt({ html: true, linkify: false, breaks: false });
+const bold = schema.marks.bold.create();
+const italic = schema.marks.italic.create();
+const link = schema.marks.link.create({ href: 'https://example.com' });
+
+function paragraph(segments) {
+  return schema.node(
+    'paragraph',
+    null,
+    segments.map(({ text, marks }) => schema.text(text, marks))
+  );
+}
+
+function assertMarkdown(segments, expected, expectedHtml) {
+  const serialized = serializeInlineMarkdown(paragraph(segments));
+  assert.equal(serialized, expected);
+  assert.equal(markdown.render(serialized), `${expectedHtml}\n`);
+}
+
+test('keeps bold open when a link ends the marked span', () => {
+  assertMarkdown(
+    [
+      { text: 'Bold ', marks: [bold] },
+      { text: 'link', marks: [link, bold] }
+    ],
+    '**Bold [link](https://example.com)**',
+    '<p><strong>Bold <a href="https://example.com">link</a></strong></p>'
+  );
+});
+
+test('keeps bold open when a link starts the marked span', () => {
+  assertMarkdown(
+    [
+      { text: 'link', marks: [link, bold] },
+      { text: ' bold', marks: [bold] }
+    ],
+    '**[link](https://example.com) bold**',
+    '<p><strong><a href="https://example.com">link</a> bold</strong></p>'
+  );
+});
+
+test('keeps one bold span around a link in the middle', () => {
+  assertMarkdown(
+    [
+      { text: 'Before ', marks: [bold] },
+      { text: 'link', marks: [link, bold] },
+      { text: ' after', marks: [bold] }
+    ],
+    '**Before [link](https://example.com) after**',
+    '<p><strong>Before <a href="https://example.com">link</a> after</strong></p>'
+  );
+});
+
+test('keeps nested bold and italic marks open across a link', () => {
+  assertMarkdown(
+    [
+      { text: 'Nested ', marks: [bold, italic] },
+      { text: 'link', marks: [link, bold, italic] },
+      { text: ' marks', marks: [bold, italic] }
+    ],
+    '***Nested [link](https://example.com) marks***',
+    '<p><em><strong>Nested <a href="https://example.com">link</a> marks</strong></em></p>'
+  );
+});
+
+test('preserves wiki-link aliases inside a bold span', () => {
+  const wikiLink = schema.marks.wikiLink.create({ title: 'Target note', aliased: true });
+  const serialized = serializeInlineMarkdown(
+    paragraph([
+      { text: 'See ', marks: [bold] },
+      { text: 'this note', marks: [wikiLink, bold] },
+      { text: ' now', marks: [bold] }
+    ])
+  );
+
+  assert.equal(serialized, '**See [[Target note|this note]] now**');
+});