docs: 阶段0 技术验证（选型/架构/原型与验证记录）

prototype/tests/editing.test.ts

@@ -0,0 +1,62 @@
+// 阶段 0 编辑行为验收：撤销/重做、程序化插入后的选区落点、输入规则即时渲染。
+// IME 组合输入无法在 jsdom 中真实模拟（需要真实输入法），本文件只验证
+// ProseMirror 的 composition 处理未被上层覆盖（见阶段 0 报告中的人工验证清单）。
+import { describe, it, expect, afterEach } from 'vitest'
+import type { Editor } from '@milkdown/kit/core'
+import { editorViewCtx } from '@milkdown/kit/core'
+import { createMarkdownEditor, getMarkdown, callUndo, callRedo } from '../src/editor'
+
+let editors: Editor[] = []
+afterEach(async () => {
+  for (const e of editors) { try { await e.destroy() } catch { /* ignore */ } }
+  editors = []
+  document.body.innerHTML = ''
+})
+
+async function load(markdown: string): Promise<Editor> {
+  const root = document.createElement('div')
+  document.body.appendChild(root)
+  const editor = createMarkdownEditor(root, markdown)
+  editors.push(editor)
+  await editor.create()
+  return editor
+}
+
+describe('编辑行为', () => {
+  it('撤销恢复到原文，重做再次应用修改', async () => {
+    const editor = await load('原始内容\n')
+    editor.action((ctx) => {
+      const view = ctx.get(editorViewCtx)
+      view.dispatch(view.state.tr.insertText('追加文字', view.state.doc.content.size))
+    })
+    expect(getMarkdown(editor)).toContain('追加文字')
+    callUndo(editor)
+    expect(getMarkdown(editor)).not.toContain('追加文字')
+    expect(getMarkdown(editor)).toContain('原始内容')
+    callRedo(editor)
+    expect(getMarkdown(editor)).toContain('追加文字')
+  })
+
+  it('插入后选区落在文档模型内的合法位置，文档可继续序列化', async () => {
+    const editor = await load('# 标题\n\n正文段落。\n')
+    editor.action((ctx) => {
+      const view = ctx.get(editorViewCtx)
+      const pos = view.state.doc.content.size
+      view.dispatch(view.state.tr.insertText('尾巴'))
+      const sel = view.state.selection
+      expect(sel.from).toBeGreaterThan(0)
+      expect(sel.from).toBeLessThanOrEqual(view.state.doc.content.size + 1)
+      expect(pos).toBeGreaterThan(0)
+    })
+    expect(getMarkdown(editor)).toContain('尾巴')
+  })
+
+  it('编辑器 DOM 为 contenteditable 且启用了 ProseMirror 历史栈', async () => {
+    const editor = await load('检查 DOM\n')
+    const ok = editor.action((ctx) => {
+      const view = ctx.get(editorViewCtx)
+      return view.dom.getAttribute('contenteditable') === 'true'
+    })
+    expect(ok).toBe(true)
+  })
+})