# Browser APIs

> **适用场景**：当测试的功能依赖浏览器原生 API 时使用——地理定位（geolocation）、权限（permissions）、剪贴板（clipboard）、通知（notifications）、摄像头/麦克风、localStorage、sessionStorage、IndexedDB。
> **前置条件**：[core/configuration.md](configuration.md)、[core/fixtures-and-hooks.md](fixtures-and-hooks.md)

## 快速参考

```typescript
// 地理定位 —— 通过上下文选项设置
const context = await browser.newContext({
  geolocation: { latitude: 40.7128, longitude: -74.006 },
  permissions: ["geolocation"],
})

// 权限 —— 在上下文层面授予
const context = await browser.newContext({
  permissions: ["clipboard-read", "clipboard-write", "notifications"],
})

// localStorage / sessionStorage —— 通过 page.evaluate 访问
await page.evaluate(() => localStorage.setItem("theme", "dark"))
const value = await page.evaluate(() => localStorage.getItem("theme"))

// 剪贴板 —— 在页面上下文中读写
await page.evaluate(() => navigator.clipboard.writeText("copied text"))
```

## 模式

### 地理定位

**适用场景**：你的应用使用 `navigator.geolocation` 来实现地图、门店定位器、配送跟踪或基于位置的功能。
**避免场景**：你的应用从不读取用户位置。

地理定位在上下文级别设置。你也可以在测试过程中使用 `context.setGeolocation()` 更新它。

**TypeScript**

```typescript
import { test, expect } from "@playwright/test"

test("根据地理定位显示最近的门店", async ({ browser }) => {
  const context = await browser.newContext({
    geolocation: { latitude: 40.7128, longitude: -74.006 }, // 纽约
    permissions: ["geolocation"],
  })
  const page = await context.newPage()

  await page.goto("/store-locator")
  await page.getByRole("button", { name: "Find nearby stores" }).click()

  await expect(page.getByText("Manhattan Store")).toBeVisible()
  await context.close()
})

test("在测试中途更新用户位置", async ({ browser }) => {
  const context = await browser.newContext({
    geolocation: { latitude: 37.7749, longitude: -122.4194 }, // 旧金山
    permissions: ["geolocation"],
  })
  const page = await context.newPage()

  await page.goto("/delivery-tracker")
  await expect(page.getByTestId("current-city")).toHaveText("San Francisco")

  // 模拟用户移动到新位置
  await context.setGeolocation({ latitude: 34.0522, longitude: -118.2437 }) // 洛杉矶

  // 触发位置刷新
  await page.getByRole("button", { name: "Update location" }).click()
  await expect(page.getByTestId("current-city")).toHaveText("Los Angeles")

  await context.close()
})
```

**JavaScript**

```javascript
const { test, expect } = require("@playwright/test")

test("根据地理定位显示最近的门店", async ({ browser }) => {
  const context = await browser.newContext({
    geolocation: { latitude: 40.7128, longitude: -74.006 },
    permissions: ["geolocation"],
  })
  const page = await context.newPage()

  await page.goto("/store-locator")
  await page.getByRole("button", { name: "Find nearby stores" }).click()

  await expect(page.getByText("Manhattan Store")).toBeVisible()
  await context.close()
})

test("在测试中途更新位置", async ({ browser }) => {
  const context = await browser.newContext({
    geolocation: { latitude: 37.7749, longitude: -122.4194 },
    permissions: ["geolocation"],
  })
  const page = await context.newPage()

  await page.goto("/delivery-tracker")
  await expect(page.getByTestId("current-city")).toHaveText("San Francisco")

  await context.setGeolocation({ latitude: 34.0522, longitude: -118.2437 })
  await page.getByRole("button", { name: "Update location" }).click()
  await expect(page.getByTestId("current-city")).toHaveText("Los Angeles")

  await context.close()
})
```

你也可以在 `playwright.config` 中全局设置地理定位：

```typescript
// playwright.config.ts
import { defineConfig } from "@playwright/test"

export default defineConfig({
  use: {
    geolocation: { latitude: 51.5074, longitude: -0.1278 }, // 伦敦
    permissions: ["geolocation"],
  },
})
```

### 权限

**适用场景**：你的应用请求浏览器权限——通知、摄像头、麦克风、地理定位、剪贴板。
**避免场景**：你的应用不使用 Permissions API。

在创建上下文时授予权限。Playwright 不显示权限对话框；你可以预先授予或拒绝它们。

**TypeScript**

```typescript
import { test, expect } from "@playwright/test"

test("授予通知权限后显示通知 UI", async ({ browser }) => {
  const context = await browser.newContext({
    permissions: ["notifications"],
  })
  const page = await context.newPage()

  await page.goto("/settings/notifications")

  // 应用检查 Notification.permission 并显示开关
  await expect(page.getByRole("switch", { name: "Enable notifications" })).toBeEnabled()

  await context.close()
})

test("拒绝通知权限后显示升级提示", async ({ browser }) => {
  // permissions 中不含 'notifications' = 已拒绝
  const context = await browser.newContext({
    permissions: [],
  })
  const page = await context.newPage()

  await page.goto("/settings/notifications")

  await expect(page.getByText("Notifications are blocked")).toBeVisible()
  await context.close()
})

test("在测试中途授予权限", async ({ browser }) => {
  const context = await browser.newContext()
  const page = await context.newPage()
  await page.goto("/camera-app")

  // 初始状态下没有摄像头权限
  await expect(page.getByText("Camera access needed")).toBeVisible()

  // 动态授予权限
  await context.grantPermissions(["camera"], { origin: "https://localhost:3000" })

  await page.getByRole("button", { name: "Enable camera" }).click()
  await expect(page.getByTestId("camera-preview")).toBeVisible()

  // 撤销所有权限
  await context.clearPermissions()
  await context.close()
})
```

**JavaScript**

```javascript
const { test, expect } = require("@playwright/test")

test("授予通知权限后显示通知 UI", async ({ browser }) => {
  const context = await browser.newContext({
    permissions: ["notifications"],
  })
  const page = await context.newPage()

  await page.goto("/settings/notifications")
  await expect(page.getByRole("switch", { name: "Enable notifications" })).toBeEnabled()
  await context.close()
})

test("在测试中途授予权限", async ({ browser }) => {
  const context = await browser.newContext()
  const page = await context.newPage()
  await page.goto("/camera-app")

  await context.grantPermissions(["camera"], { origin: "https://localhost:3000" })
  await page.getByRole("button", { name: "Enable camera" }).click()
  await expect(page.getByTestId("camera-preview")).toBeVisible()

  await context.clearPermissions()
  await context.close()
})
```

### Clipboard API

**适用场景**：测试复制/粘贴功能、"复制到剪贴板"按钮或从剪贴板粘贴的功能。
**避免场景**：你的应用不操作剪贴板。

**TypeScript**

```typescript
import { test, expect } from "@playwright/test"

test("复制按钮将文本放入剪贴板", async ({ browser }) => {
  const context = await browser.newContext({
    permissions: ["clipboard-read", "clipboard-write"],
  })
  const page = await context.newPage()

  await page.goto("/share")
  await page.getByRole("button", { name: "Copy link" }).click()

  // 读取剪贴板内容
  const clipboardText = await page.evaluate(() => navigator.clipboard.readText())
  expect(clipboardText).toContain("https://example.com/share/")

  await context.close()
})

test("从剪贴板粘贴到编辑器", async ({ browser }) => {
  const context = await browser.newContext({
    permissions: ["clipboard-read", "clipboard-write"],
  })
  const page = await context.newPage()

  await page.goto("/editor")

  // 以编程方式写入剪贴板
  await page.evaluate(() => navigator.clipboard.writeText("Pasted content from clipboard"))

  // 聚焦编辑器并触发粘贴
  const editor = page.getByRole("textbox", { name: "Editor" })
  await editor.focus()
  await page.keyboard.press("ControlOrMeta+v")

  await expect(editor).toContainText("Pasted content from clipboard")

  await context.close()
})
```

**JavaScript**

```javascript
const { test, expect } = require("@playwright/test")

test("复制按钮将文本放入剪贴板", async ({ browser }) => {
  const context = await browser.newContext({
    permissions: ["clipboard-read", "clipboard-write"],
  })
  const page = await context.newPage()

  await page.goto("/share")
  await page.getByRole("button", { name: "Copy link" }).click()

  const clipboardText = await page.evaluate(() => navigator.clipboard.readText())
  expect(clipboardText).toContain("https://example.com/share/")
  await context.close()
})
```

### 摄像头与麦克风模拟

**适用场景**：测试视频通话、二维码扫描器、语音录制，或任何使用 `getUserMedia` 的功能。
**避免场景**：你的应用不使用摄像头或麦克风。

Chromium 可以使用虚拟媒体设备。此功能在 Firefox 或 WebKit 中不可用。

**TypeScript**

```typescript
import { test, expect, chromium } from "@playwright/test"

test("视频通话使用虚拟摄像头显示本地预览", async () => {
  // 使用虚拟媒体流启动 Chromium
  const browser = await chromium.launch({
    args: ["--use-fake-device-for-media-stream", "--use-fake-ui-for-media-stream"],
  })

  const context = await browser.newContext({
    permissions: ["camera", "microphone"],
  })
  const page = await context.newPage()

  await page.goto("/video-call")
  await page.getByRole("button", { name: "Start camera" }).click()

  // 验证视频元素正在播放
  const isPlaying = await page.evaluate(() => {
    const video = document.querySelector("video#local-preview") as HTMLVideoElement
    return video && !video.paused && video.readyState >= 2
  })
  expect(isPlaying).toBe(true)

  await context.close()
  await browser.close()
})
```

**JavaScript**

```javascript
const { test, expect, chromium } = require("@playwright/test")

test("视频通话使用虚拟摄像头显示本地预览", async () => {
  const browser = await chromium.launch({
    args: ["--use-fake-device-for-media-stream", "--use-fake-ui-for-media-stream"],
  })

  const context = await browser.newContext({
    permissions: ["camera", "microphone"],
  })
  const page = await context.newPage()

  await page.goto("/video-call")
  await page.getByRole("button", { name: "Start camera" }).click()

  const isPlaying = await page.evaluate(() => {
    const video = document.querySelector("video#local-preview")
    return video && !video.paused && video.readyState >= 2
  })
  expect(isPlaying).toBe(true)

  await context.close()
  await browser.close()
})
```

### localStorage 与 sessionStorage

**适用场景**：你的应用在 Web 存储中持久化状态、令牌、偏好设置或功能开关。
**避免场景**：你可以通过 UI 或 API 设置状态。为真实性考虑，优先采用这些方式。

**TypeScript**

```typescript
import { test, expect } from "@playwright/test"

test("应用从 localStorage 偏好设置加载深色主题", async ({ page }) => {
  // 在导航前设置 localStorage
  await page.goto("/")
  await page.evaluate(() => localStorage.setItem("theme", "dark"))

  // 重新加载以应用存储的偏好
  await page.reload()

  await expect(page.locator("html")).toHaveAttribute("data-theme", "dark")
})

test("在场景之间清除 localStorage", async ({ page }) => {
  await page.goto("/")

  // 写入一些数据
  await page.evaluate(() => {
    localStorage.setItem("cart", JSON.stringify([{ id: 1, qty: 2 }]))
    localStorage.setItem("user_prefs", JSON.stringify({ currency: "EUR" }))
  })

  // 读取并验证
  const cart = await page.evaluate(() => JSON.parse(localStorage.getItem("cart") || "[]"))
  expect(cart).toHaveLength(1)

  // 清除特定键
  await page.evaluate(() => localStorage.removeItem("cart"))

  // 或者清除所有内容
  await page.evaluate(() => localStorage.clear())
})

test("sessionStorage 在会话内的导航中保持不变", async ({ page }) => {
  await page.goto("/step-1")
  await page.evaluate(() => sessionStorage.setItem("wizard_step", "1"))

  await page.goto("/step-2")
  const step = await page.evaluate(() => sessionStorage.getItem("wizard_step"))
  expect(step).toBe("1")
})
```

**JavaScript**

```javascript
const { test, expect } = require("@playwright/test")

test("应用从 localStorage 偏好设置加载深色主题", async ({ page }) => {
  await page.goto("/")
  await page.evaluate(() => localStorage.setItem("theme", "dark"))
  await page.reload()

  await expect(page.locator("html")).toHaveAttribute("data-theme", "dark")
})

test("sessionStorage 在会话内的导航中保持不变", async ({ page }) => {
  await page.goto("/step-1")
  await page.evaluate(() => sessionStorage.setItem("wizard_step", "1"))

  await page.goto("/step-2")
  const step = await page.evaluate(() => sessionStorage.getItem("wizard_step"))
  expect(step).toBe("1")
})
```

### IndexedDB 测试

**适用场景**：你的应用使用 IndexedDB 进行离线存储、缓存或大数据集（渐进式 Web 应用、离线优先应用）。
**避免场景**：你的应用仅使用 localStorage 或服务端存储。

**TypeScript**

```typescript
import { test, expect } from "@playwright/test"

test("离线优先应用将数据存储在 IndexedDB 中", async ({ page }) => {
  await page.goto("/notes")

  // 通过 UI 创建笔记
  await page.getByRole("button", { name: "New note" }).click()
  await page.getByRole("textbox", { name: "Title" }).fill("Test Note")
  await page.getByRole("textbox", { name: "Content" }).fill("This is stored in IndexedDB")
  await page.getByRole("button", { name: "Save" }).click()

  // 验证它已存储在 IndexedDB 中
  const storedNotes = await page.evaluate(() => {
    return new Promise((resolve, reject) => {
      const request = indexedDB.open("NotesDB", 1)
      request.onsuccess = () => {
        const db = request.result
        const tx = db.transaction("notes", "readonly")
        const store = tx.objectStore("notes")
        const getAll = store.getAll()
        getAll.onsuccess = () => resolve(getAll.result)
        getAll.onerror = () => reject(getAll.error)
      }
      request.onerror = () => reject(request.error)
    })
  })

  expect(storedNotes).toHaveLength(1)
  expect(storedNotes[0]).toMatchObject({
    title: "Test Note",
    content: "This is stored in IndexedDB",
  })
})

test("清除 IndexedDB 以获取干净的测试状态", async ({ page }) => {
  await page.goto("/")

  // 删除整个数据库
  await page.evaluate(() => {
    return new Promise((resolve, reject) => {
      const request = indexedDB.deleteDatabase("NotesDB")
      request.onsuccess = () => resolve(undefined)
      request.onerror = () => reject(request.error)
    })
  })

  await page.reload()
  await expect(page.getByText("No notes yet")).toBeVisible()
})
```

**JavaScript**

```javascript
const { test, expect } = require("@playwright/test")

test("离线优先应用将数据存储在 IndexedDB 中", async ({ page }) => {
  await page.goto("/notes")

  await page.getByRole("button", { name: "New note" }).click()
  await page.getByRole("textbox", { name: "Title" }).fill("Test Note")
  await page.getByRole("textbox", { name: "Content" }).fill("This is stored in IndexedDB")
  await page.getByRole("button", { name: "Save" }).click()

  const storedNotes = await page.evaluate(() => {
    return new Promise((resolve, reject) => {
      const request = indexedDB.open("NotesDB", 1)
      request.onsuccess = () => {
        const db = request.result
        const tx = db.transaction("notes", "readonly")
        const store = tx.objectStore("notes")
        const getAll = store.getAll()
        getAll.onsuccess = () => resolve(getAll.result)
        getAll.onerror = () => reject(getAll.error)
      }
      request.onerror = () => reject(request.error)
    })
  })

  expect(storedNotes).toHaveLength(1)
  expect(storedNotes[0]).toMatchObject({
    title: "Test Note",
    content: "This is stored in IndexedDB",
  })
})
```

### 通知

**适用场景**：你的应用使用浏览器 Notification API 显示桌面通知。
**避免场景**：通知纯粹是服务端触发的（不涉及 Notification API 的推送）。

Playwright 无法捕获实际的系统通知。取而代之的是，模拟 Notification 构造函数并验证应用是否正确调用了它。

**TypeScript**

```typescript
import { test, expect } from "@playwright/test"

test("应用在收到新消息时触发浏览器通知", async ({ browser }) => {
  const context = await browser.newContext({
    permissions: ["notifications"],
  })
  const page = await context.newPage()

  // 拦截 Notification 构造函数以捕获调用
  await page.evaluate(() => {
    ;(window as any).__notifications = []
    const OriginalNotification = window.Notification
    ;(window as any).Notification = class MockNotification {
      constructor(title: string, options?: NotificationOptions) {
        ;(window as any).__notifications.push({ title, ...options })
      }
      static get permission() {
        return "granted"
      }
      static requestPermission() {
        return Promise.resolve("granted" as NotificationPermission)
      }
    }
  })

  await page.goto("/chat")

  // 模拟收到一条会触发通知的消息
  await page.evaluate(() => {
    window.dispatchEvent(
      new CustomEvent("new-message", {
        detail: { from: "Alice", text: "Hey there!" },
      })
    )
  })

  // 检查通知是否以正确的内容创建
  const notifications = await page.evaluate(() => (window as any).__notifications)
  expect(notifications).toHaveLength(1)
  expect(notifications[0].title).toBe("New message from Alice")
  expect(notifications[0].body).toBe("Hey there!")

  await context.close()
})
```

**JavaScript**

```javascript
const { test, expect } = require("@playwright/test")

test("应用在收到新消息时触发浏览器通知", async ({ browser }) => {
  const context = await browser.newContext({
    permissions: ["notifications"],
  })
  const page = await context.newPage()

  await page.evaluate(() => {
    window.__notifications = []
    window.Notification = class MockNotification {
      constructor(title, options) {
        window.__notifications.push({ title, ...options })
      }
      static get permission() {
        return "granted"
      }
      static requestPermission() {
        return Promise.resolve("granted")
      }
    }
  })

  await page.goto("/chat")

  await page.evaluate(() => {
    window.dispatchEvent(
      new CustomEvent("new-message", {
        detail: { from: "Alice", text: "Hey there!" },
      })
    )
  })

  const notifications = await page.evaluate(() => window.__notifications)
  expect(notifications).toHaveLength(1)
  expect(notifications[0].title).toBe("New message from Alice")
  await context.close()
})
```

## 决策指南

| 浏览器 API           | 测试方法                                                                               | 关键配置                                                            |
| ------------------- | -------------------------------------------------------------------------------------- | ------------------------------------------------------------------ |
| 地理定位（Geolocation） | `geolocation` 上下文选项 + `permissions: ['geolocation']`                               | `context.setGeolocation()` 用于测试中途变更                         |
| 权限（任意）           | 上下文选项中的 `permissions` 数组                                                        | `context.grantPermissions()` / `context.clearPermissions()`        |
| 剪贴板（Clipboard）    | 授予 `clipboard-read`/`clipboard-write` + `page.evaluate(navigator.clipboard...)`       | 需要安全上下文（HTTPS 或 localhost）                                 |
| 通知（Notifications）  | 通过 `page.evaluate` 模拟 `Notification` 构造函数                                        | 授予 `notifications` 权限；捕获构造函数调用                          |
| 摄像头/麦克风          | Chromium 启动参数 `--use-fake-device-for-media-stream`                                 | 仅在 Chromium 中有效；授予 `camera`/`microphone` 权限               |
| localStorage         | `page.evaluate(() => localStorage.getItem/setItem(...))`                               | 在导航或重新加载前设置才能生效                                      |
| sessionStorage       | `page.evaluate(() => sessionStorage.getItem/setItem(...))`                             | 作用域限定于当前浏览会话；上下文关闭时清除                          |
| IndexedDB            | 使用 `indexedDB.open()` 的 `page.evaluate`                                              | 对异步操作需用 Promise 包裹                                        |

## 反模式

| 不要这样做                                               | 问题                                                       | 应这样做                                                                      |
| ------------------------------------------------------- | ---------------------------------------------------------- | ------------------------------------------------------------------------------ |
| 设置 `geolocation` 但不授予权限                           | `getCurrentPosition` 返回权限错误                            | 始终将 `geolocation` 与 `permissions: ['geolocation']` 配对                     |
| 在非安全上下文中测试剪贴板                                 | `navigator.clipboard` 在非 HTTPS 上下文中抛出异常           | 使用 `localhost` 或在测试服务器中配置 HTTPS                                    |
| 在导航到目标源之前访问 localStorage                       | `page.evaluate` 最初在 `about:blank` 上下文中执行           | 先执行 `page.goto('/')`，然后设置 localStorage，再重新加载                     |
| 直接在 localStorage 中存储测试令牌                        | 绕过认证流程；可能掩盖真实的登录缺陷                         | 使用 `storageState` 或合适的认证 fixture                                       |
| 依赖上一个测试的 IndexedDB 状态                            | 测试必须相互独立                                           | 在测试设置中清除或删除数据库                                                   |
| 不清除注入的模拟（Notification 等）                        | 如果使用同一个上下文，模拟会泄漏到后续测试中                 | 默认每个测试使用新的上下文；仅在使用共享上下文时需要注意                        |

## 故障排查

| 症状                                                       | 原因                                                       | 修复方法                                                                         |
| --------------------------------------------------------- | ---------------------------------------------------------- | -------------------------------------------------------------------------------- |
| 应用中 `geolocation` 返回 `undefined`                      | 未授予权限                                                 | 在上下文选项中添加 `permissions: ['geolocation']`                                 |
| 剪贴板 `readText()` 抛出 `DOMException`                    | 缺少剪贴板权限或非安全上下文                                | 授予 `clipboard-read`；确保使用 HTTPS 或 localhost                               |
| `localStorage.getItem()` 在 `setItem` 后返回 `null`        | 设置操作在不同的源上执行，或在导航之前执行                  | 验证你已在调用 `setItem` 之前导航到正确的源                                       |
| 摄像头在 Firefox/WebKit 中无法工作                          | 虚拟媒体设备仅 Chromium 支持                                | 在非 Chromium 浏览器上跳过摄像头测试，或通过 `page.evaluate` 模拟 `getUserMedia` |
| IndexedDB 的 `evaluate` 返回 `undefined`                   | 忘记返回 Promise                                           | 确保 `page.evaluate` 回调返回 `new Promise(...)`                                  |
| 权限变更未生效                                             | 应用在加载时缓存了权限状态                                  | 在 `grantPermissions()` 或 `clearPermissions()` 之后重新加载页面                  |

## 相关文档

- [core/configuration.md](configuration.md) —— 配置中的全局地理定位/权限设置
- [core/service-workers-and-pwa.md](service-workers-and-pwa.md) —— 使用 IndexedDB 和服务工作线程进行离线与缓存测试
- [core/fixtures-and-hooks.md](fixtures-and-hooks.md) —— 将浏览器 API 设置封装为可复用的 fixture
- [core/debugging.md](debugging.md) —— 在 Playwright 追踪中检查存储和权限