fix(editor): preserve ordered list continuation columns

src/renderer/src/components/editor/rich-markdown-extensions.ts

@@ -38,6 +38,7 @@ import { createRichMarkdownHtmlSuperscriptLink } from './rich-markdown-html-supe
 import type { RichMarkdownHtmlSuperscriptLinkContext } from './rich-markdown-html-superscript-link-context'
 import { RichMarkdownOrderedList } from './rich-markdown-ordered-list'
 import { RichMarkdownCodeSpanPadding } from './rich-markdown-code-span-padding'
+import { RichMarkdownListItem } from './rich-markdown-list-item'
 import { RichMarkdownParagraph } from './rich-markdown-paragraph'
 import { RichMarkdownInlineMath } from './rich-markdown-inline-math'
 import { RichMarkdownCodeBlockLowlight } from './rich-markdown-lowlight'
@@ -74,6 +75,7 @@ export function createRichMarkdownExtensions({
       link: false,
       code: false,
       codeBlock: false,
+      listItem: false,
       orderedList: false,
       paragraph: false
     }),
@@ -215,6 +217,7 @@ export function createRichMarkdownExtensions({
       inline: true
     }),
     RichMarkdownOrderedList,
+    RichMarkdownListItem,
     RichMarkdownTaskList,
     TaskItem.configure({
       nested: true

src/renderer/src/components/editor/rich-markdown-list-item.test.ts

@@ -0,0 +1,45 @@
+import { Editor } from '@tiptap/core'
+import { describe, expect, it } from 'vitest'
+import { encodeRawMarkdownHtmlForRichEditor } from './raw-markdown-html'
+import { createRichMarkdownExtensions } from './rich-markdown-extensions'
+import { createRichMarkdownEditorCodec } from './rich-markdown-source-transport'
+
+function roundTrip(source: string): string {
+  const codec = createRichMarkdownEditorCodec()
+  const editor = new Editor({
+    element: null,
+    extensions: createRichMarkdownExtensions({ codec }),
+    content: encodeRawMarkdownHtmlForRichEditor(source, codec),
+    contentType: 'markdown'
+  })
+  try {
+    return editor.getMarkdown().trimEnd()
+  } finally {
+    editor.destroy()
+  }
+}
+
+describe('ordered list continuation serialization', () => {
+  it.each([
+    ['9. item\n   continuation', '9. item\n   continuation'],
+    ['10. item\n    continuation', '10. item\n    continuation'],
+    ['10. item\n     continuation', '10. item\n    continuation'],
+    ['100. item\n     continuation', '100. item\n     continuation']
+  ])('uses the marker width for %j', (source, expected) => {
+    expect(roundTrip(source)).toBe(expected)
+  })
+
+  it('keeps multi-digit continuation text intact across repeated saves', () => {
+    const source = '10. An item mentioning the 12-step\n     write-up are in the folder.'
+    let current = source
+    for (let cycle = 0; cycle < 3; cycle += 1) {
+      current = roundTrip(current)
+    }
+    expect(current).toBe('10. An item mentioning the 12-step\n    write-up are in the folder.')
+  })
+
+  it('does not change bullet continuation formatting', () => {
+    const source = '- item\n  continuation'
+    expect(roundTrip(source)).toBe('- item\ncontinuation')
+  })
+})

src/renderer/src/components/editor/rich-markdown-list-item.ts

@@ -0,0 +1,54 @@
+import type { JSONContent, RenderContext } from '@tiptap/core'
+import { ListItem } from '@tiptap/extension-list'
+
+const BASE_INDENT = 2
+
+const baseRenderMarkdown = ListItem.config.renderMarkdown
+
+function listStart(context: RenderContext): number {
+  const start = context.meta?.parentAttrs?.start
+  return typeof start === 'number' ? start : 1
+}
+
+function markerWidth(context: RenderContext): number {
+  if (context.parentType !== 'orderedList') {
+    return 2
+  }
+  return `${listStart(context) + (context.index ?? 0)}. `.length
+}
+
+function paragraphLineCount(node: JSONContent): number {
+  const first = Array.isArray(node.content) ? node.content[0] : undefined
+  if (first?.type !== 'paragraph') {
+    return 1
+  }
+  const text = (first.content ?? [])
+    .map((child) => (child.type === 'hardBreak' ? '\n' : (child.text ?? '')))
+    .join('')
+  return text.split('\n').length
+}
+
+function indentParagraphContinuations(markdown: string, column: number): string {
+  return markdown.replace(/\n(?!\n)[ \t]*/g, `\n${' '.repeat(column)}`)
+}
+
+export const RichMarkdownListItem = ListItem.extend({
+  renderMarkdown: (node, helpers, context) => {
+    if (typeof baseRenderMarkdown !== 'function') {
+      return ''
+    }
+    if (context.parentType !== 'orderedList') {
+      return baseRenderMarkdown(node, helpers, context)
+    }
+    const width = markerWidth(context)
+    const lines = baseRenderMarkdown(node, helpers, context).split('\n')
+    const paragraphLines = paragraphLineCount(node)
+    const paragraph = indentParagraphContinuations(lines.slice(0, paragraphLines).join('\n'), width)
+    const blocks = lines
+      .slice(paragraphLines)
+      .map((line) =>
+        line === '' ? line : `${' '.repeat(Math.max(0, width - BASE_INDENT))}${line}`
+      )
+    return [paragraph, ...blocks].join('\n')
+  }
+})