---
name: webapp-testing
description: Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs.
license: Complete terms in LICENSE.txt
---

# Web Application Testing

To test local web applications, write native Python Playwright scripts.

**Helper Scripts Available**:
- `scripts/with_server.py` - Manages server lifecycle (supports multiple servers)

**Always run scripts with `--help` first** to see usage. DO NOT read the source until you try running the script first and find that a customized solution is abslutely necessary. These scripts can be very large and thus pollute your context window. They exist to be called directly as black-box scripts rather than ingested into your context window.

## Decision Tree: Choosing Your Approach

```
User task → Is it static HTML?
    ├─ Yes → Read HTML file directly to identify selectors
    │         ├─ Success → Write Playwright script using selectors
    │         └─ Fails/Incomplete → Treat as dynamic (below)
    │
    └─ No (dynamic webapp) → Is the server already running?
        ├─ No → Run: python scripts/with_server.py --help
        │        Then use the helper + write simplified Playwright script
        │
        └─ Yes → Reconnaissance-then-action:
            1. Navigate and wait for networkidle
            2. Take screenshot or inspect DOM
            3. Identify selectors from rendered state
            4. Execute actions with discovered selectors
```

## Example: Using with_server.py

To start a server, run `--help` first, then use the helper:

**Single server:**
```bash
python scripts/with_server.py --server "npm run dev" --port 5173 -- python your_automation.py
```

**Multiple servers (e.g., backend + frontend):**
```bash
python scripts/with_server.py \
  --server "cd backend && python server.py" --port 3000 \
  --server "cd frontend && npm run dev" --port 5173 \
  -- python your_automation.py
```

To create an automation script, include only Playwright logic (servers are managed automatically):
```python
from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(headless=True) # Always launch chromium in headless mode
    page = browser.new_page()
    page.goto('http://localhost:5173') # Server already running and ready
    page.wait_for_load_state('networkidle') # CRITICAL: Wait for JS to execute
    # ... your automation logic
    browser.close()
```

## Reconnaissance-Then-Action Pattern

1. **Inspect rendered DOM**:
   ```python
   page.screenshot(path='/tmp/inspect.png', full_page=True)
   content = page.content()
   page.locator('button').all()
   ```

2. **Identify selectors** from inspection results

3. **Execute actions** using discovered selectors

## Common Pitfall

❌ **Don't** inspect the DOM before waiting for `networkidle` on dynamic apps
✅ **Do** wait for `page.wait_for_load_state('networkidle')` before inspection

## Best Practices

- **Use bundled scripts as black boxes** - To accomplish a task, consider whether one of the scripts available in `scripts/` can help. These scripts handle common, complex workflows reliably without cluttering the context window. Use `--help` to see usage, then invoke directly. 
- Use `sync_playwright()` for synchronous scripts
- Always close the browser when done
- Use descriptive selectors: `text=`, `role=`, CSS selectors, or IDs
- Add appropriate waits: `page.wait_for_selector()` or `page.wait_for_timeout()`

## Reference Files

- **examples/** - Examples showing common patterns:
  - `element_discovery.py` - Discovering buttons, links, and inputs on a page
  - `static_html_automation.py` - Using file:// URLs for local HTML
  - `console_logging.py` - Capturing console logs during automation

核心功能

• Playwright自动化：支持编写原生Python Playwright脚本来测试Web应用程序

• 服务器生命周期管理：通过scripts/with_server.py脚本管理服务器启动和停止

• 多服务器支持：可以同时管理多个服务器（如后端+前端）

• DOM检查和元素发现：支持在渲染后的页面上识别选择器和元素

• 屏幕截图功能：可以捕获浏览器页面的截图用于分析

• 控制台日志捕获：支持在自动化过程中捕获浏览器控制台日志

使用场景

• 验证前端应用程序的功能

• 调试用户界面行为

• 捕获浏览器屏幕截图

• 查看和分析浏览器日志

• 自动化Web应用程序测试

• 测试本地开发服务器上的应用程序

• 测试需要JavaScript执行才能正确渲染的动态应用程序

使用方法

1. 静态HTML vs 动态应用决策：

   • 如果是静态HTML：直接读取HTML文件以识别选择器

   • 如果是动态Web应用且服务器未运行：使用scripts/with_server.py启动服务器

   • 如果服务器已运行：使用侦察然后行动模式

2. 使用with_server.py工具：

   # 单个服务器
   python scripts/with_server.py --server "npm run dev" --port 5173 -- python your_automation.py
   

   多个服务器（例如后端+前端）

   python scripts/with_server.py
--server "cd backend && python server.py" --port 3000
--server "cd frontend && npm run dev" --port 5173
-- python your_automation.py

3. 编写Playwright脚本：

   from playwright.sync_api import sync_playwright
   

   with sync_playwright() as p:
browser = p.chromium.launch(headless=True) # 始终以无头模式启动chromium
page = browser.new_page()
page.goto('http://localhost:5173') # 服务器已经运行并就绪
page.wait_for_load_state('networkidle') # 关键：等待JavaScript执行完成
# ... 你的自动化逻辑
browser.close()

4. 侦察然后行动模式：

   • 导航并等待网络空闲

   • 截图或检查DOM

   • 从渲染状态中识别选择器

   • 使用发现的选择器执行操作

许可证类型

Apache许可证 2.0版本 (Apache License Version 2.0)，允许自由使用、复制、修改和分发，但需保留版权声明和许可证声明。该许可证提供了专利许可，并对责任进行了限制。