test: App 与 main 函数覆盖提升至 90%+（右键操作/右侧面板/解码回退/入口）

src/renderer/src/__tests__/App.test.tsx

@@ -18,10 +18,18 @@ function mockApi(overrides?: Partial<typeof window.api>): typeof window.api {
   return { ...base, ...overrides } as typeof window.api
 }
 
+let clipboardSpy: ReturnType<typeof vi.fn>
+
 beforeEach(() => {
   window.api = mockApi()
   // jsdom 未实现 scrollIntoView，导航定位需要打桩
   Element.prototype.scrollIntoView = vi.fn()
+  // jsdom 未实现 navigator.clipboard，右键复制需要打桩
+  clipboardSpy = vi.fn()
+  Object.defineProperty(navigator, 'clipboard', {
+    value: { writeText: clipboardSpy },
+    configurable: true
+  })
 })
 
 describe('App - 初始空态', () => {
@@ -105,6 +113,19 @@ describe('App - 拖拽导入', () => {
     fireEvent.dragLeave(pane)
     expect(pane.className).not.toContain('dragging')
   })
+
+  it('解码失败时回退 file.text（覆盖 dropPane catch 分支）', async () => {
+    window.api = mockApi({
+      decodeBuffer: async () => {
+        throw new Error('boom')
+      }
+    })
+    render(<App />)
+    const file = new File(['fallback1'], 'd.txt', { type: 'text/plain' })
+    const pane = screen.getByText(/选择左侧文件/).closest('.pane-empty') as Element
+    fireEvent.drop(pane, { dataTransfer: { files: [file] } })
+    expect(await screen.findByText('导出报告')).toBeInTheDocument()
+  })
 })
 
 describe('App - 差异导航与清空', () => {
@@ -124,4 +145,69 @@ describe('App - 差异导航与清空', () => {
     fireEvent.click(screen.getByText('清空'))
     expect(await screen.findByText(/选择左侧文件/)).toBeInTheDocument()
   })
+})
+
+describe('App - 空态打开按钮', () => {
+  it('点击空面板的打开文件按钮加载左侧文件', async () => {
+    render(<App />)
+    fireEvent.click(screen.getAllByText('打开文件')[0])
+    expect(await screen.findByText('导出报告')).toBeInTheDocument()
+  })
+})
+
+describe('App - 右键菜单操作', () => {
+  it('执行复制本行内容并关闭菜单', async () => {
+    render(<App />)
+    fireEvent.click(screen.getByText('打开左侧'))
+    await screen.findByText('导出报告')
+    fireEvent.contextMenu((await screen.findAllByText(/line1/))[0])
+    fireEvent.click(await screen.findByText('复制左侧此行内容'))
+    expect(clipboardSpy).toHaveBeenCalled()
+    expect(screen.queryByText('复制左侧此行内容')).not.toBeInTheDocument()
+  })
+
+  it('执行复制文件名', async () => {
+    render(<App />)
+    fireEvent.click(screen.getByText('打开左侧'))
+    await screen.findByText('导出报告')
+    fireEvent.contextMenu((await screen.findAllByText(/line1/))[0])
+    fireEvent.click(await screen.findByText('复制文件名'))
+    expect(clipboardSpy).toHaveBeenCalledWith('a.txt')
+  })
+
+  it('执行在文件夹中显示（覆盖 showInFolder）', async () => {
+    const showInFolder = vi.fn(async () => true)
+    window.api = mockApi({ showInFolder })
+    render(<App />)
+    fireEvent.click(screen.getByText('打开左侧'))
+    await screen.findByText('导出报告')
+    fireEvent.contextMenu((await screen.findAllByText(/line1/))[0])
+    fireEvent.click(await screen.findByText('在文件夹中显示'))
+    expect(showInFolder).toHaveBeenCalledWith('/tmp/a.txt')
+  })
+})
+
+describe('App - 右侧面板交互', () => {
+  it('点击右侧打开文件按钮加载', async () => {
+    render(<App />)
+    fireEvent.click(screen.getAllByText('打开文件')[1])
+    expect(await screen.findByText('导出报告')).toBeInTheDocument()
+  })
+
+  it('右侧拖拽悬停/离开高亮切换', () => {
+    render(<App />)
+    const pane = screen.getByText(/选择右侧文件/).closest('.pane-empty') as Element
+    fireEvent.dragOver(pane)
+    expect(pane.className).toContain('dragging')
+    fireEvent.dragLeave(pane)
+    expect(pane.className).not.toContain('dragging')
+  })
+
+  it('右侧拖放加载（覆盖右侧 onDrop 与 dropPane 右分支）', async () => {
+    render(<App />)
+    const file = new File(['r1\nr2'], 'e.txt', { type: 'text/plain' })
+    const pane = screen.getByText(/选择右侧文件/).closest('.pane-empty') as Element
+    fireEvent.drop(pane, { dataTransfer: { files: [file] } })
+    expect(await screen.findByText('导出报告')).toBeInTheDocument()
+  })
 })

src/renderer/src/__tests__/main.test.ts

@@ -0,0 +1,20 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { screen, act } from '@testing-library/react'
+
+// main.tsx 引入全局样式，测试中替换为空模块避免 CSS 处理
+vi.mock('../styles/global.css', () => ({}))
+
+describe('main 入口', () => {
+  beforeEach(() => {
+    document.body.innerHTML = '<div id="root"></div>'
+    vi.resetModules()
+  })
+
+  it('挂载 DiffLens 应用（覆盖 main.tsx 入口）', async () => {
+    await act(async () => {
+      await import('../main')
+    })
+    expect(document.getElementById('root')).toBeTruthy()
+    expect(await screen.findByText('DiffLens')).toBeInTheDocument()
+  })
+})