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Pytest 插件参考

介绍

🌐 Introduction

Playwright 提供了一个 Pytest 插件,用于编写端到端测试。要开始使用它,请参考 入门指南

🌐 Playwright provides a Pytest plugin to write end-to-end tests. To get started with it, refer to the getting started guide.

用法

🌐 Usage

要运行你的测试,请使用 Pytest 命令行工具。

🌐 To run your tests, use Pytest CLI.

pytest --browser webkit --headed

如果你想自动添加 CLI 参数而无需手动指定,可以使用 pytest.ini 文件:

🌐 If you want to add the CLI arguments automatically without specifying them, you can use the pytest.ini file:

# content of pytest.ini
[pytest]
# Run firefox with UI
addopts = --headed --browser firefox

CLI 参数

🌐 CLI arguments

请注意,CLI 参数仅适用于默认的 browsercontextpage 夹具。如果你通过像 browser.new_context() 这样的 API 调用创建浏览器、上下文或页面,CLI 参数将不会被应用。

🌐 Note that CLI arguments are only applied to the default browser, context and page fixtures. If you create a browser, a context or a page with the API call like browser.new_context(), the CLI arguments are not applied.

  • --headed:以有头模式运行测试(默认值:无头模式)。
  • --browser:在不同的浏览器 chromiumfirefoxwebkit 中运行测试。可以多次指定(默认:chromium)。
  • --browser-channel Browser channel to be used.
  • --slowmo 会将 Playwright 操作减慢指定的毫秒数。这样做很有用,可以让你看到发生了什么(默认值:0)。
  • --device Device to be emulated.
  • --output 目录用于存放测试产生的工件(默认:test-results)。
  • --tracing 是否为每个测试记录跟踪onoffretain-on-failure(默认:off)。
  • --video 是否为每次测试录制视频。onoffretain-on-failure(默认:off)。
  • --screenshot 是否在每次测试后自动截取屏幕截图。onoffonly-on-failure(默认:off)。
  • --full-page-screenshot 是否在失败时截取整页截图。默认情况下,只截取可视区域。需要启用 --screenshot(默认值:off)。

夹具

🌐 Fixtures

此插件配置了针对 Playwright 的 pytest 夹具。要使用这些夹具,请在测试函数中将夹具名称作为参数使用。

🌐 This plugin configures Playwright-specific fixtures for pytest. To use these fixtures, use the fixture name as an argument to the test function.

def test_my_app_is_working(fixture_name):
pass
# Test using fixture_name
# ...

函数作用域:这些测试夹具在测试函数中被请求时创建,并在测试结束时销毁。

会话范围:这些测试夹具在测试函数中被请求时创建,并在所有测试结束时销毁。

  • playwrightPlaywright 实例。
  • browser_typeBrowserType 当前浏览器的实例。
  • browser:由 Playwright 启动的 浏览器 实例。
  • browser_name:浏览器名称为字符串。
  • browser_channel:浏览器通道为字符串。
  • is_chromiumis_webkitis_firefox:分别对应浏览器类型的布尔值。

自定义夹具选项:对于 browsercontext 夹具,使用以下夹具来定义自定义启动选项。

  • browser_type_launch_args:重写 browser_type.launch() 的启动参数。它应返回一个字典。
  • browser_context_args:重写 browser.new_context() 的选项。它应该返回一个字典。
  • connect_options:通过 WebSocket 端点连接到现有浏览器。它应该返回一个包含 browser_type.connect() 选项的字典。

也可以通过使用 browser_context_args 标记来为单个测试覆盖上下文选项 (browser.new_context()):

🌐 Its also possible to override the context options (browser.new_context()) for a single test by using the browser_context_args marker:

import pytest

@pytest.mark.browser_context_args(timezone_id="Europe/Berlin", locale="en-GB")
def test_browser_context_args(page):
assert page.evaluate("window.navigator.userAgent") == "Europe/Berlin"
assert page.evaluate("window.navigator.languages") == ["de-DE"]

并行处理:同时运行多个测试

🌐 Parallelism: Running Multiple Tests at Once

如果你的测试在一台拥有大量CPU的机器上运行,你可以使用 pytest-xdist 同时运行多个测试,从而加快整个测试套件的执行时间:

🌐 If your tests are running on a machine with a lot of CPUs, you can speed up the overall execution time of your test suite by using pytest-xdist to run multiple tests at once:

# install dependency
pip install pytest-xdist
# use the --numprocesses flag
pytest --numprocesses auto

根据硬件和测试的性质,你可以将 numprocesses 设置在 2 到机器 CPU 数量之间的任何值。如果设置过高,可能会出现意想不到的行为。

🌐 Depending on the hardware and nature of your tests, you can set numprocesses to be anywhere from 2 to the number of CPUs on the machine. If set too high, you may notice unexpected behavior.

有关 pytest 选项的一般信息,请参见 运行测试

🌐 See Running Tests for general information on pytest options.

示例

🌐 Examples

配置自动补齐的类型

🌐 Configure typings for auto-completion

test_my_application.py
from playwright.sync_api import Page

def test_visit_admin_dashboard(page: Page):
page.goto("/admin")
# ...

如果你在使用带有 Pylance 的 VSCode,可以通过启用 python.testing.pytestEnabled 设置来推断这些类型,这样就不需要类型注解了。

🌐 If you're using VSCode with Pylance, these types can be inferred by enabling the python.testing.pytestEnabled setting so you don't need the type annotation.

使用多个上下文

🌐 Using multiple contexts

为了模拟多个用户,你可以创建多个 BrowserContext 实例。

🌐 In order to simulate multiple users, you can create multiple BrowserContext instances.

test_my_application.py
from playwright.sync_api import Page, BrowserContext
from pytest_playwright.pytest_playwright import CreateContextCallback

def test_foo(page: Page, new_context: CreateContextCallback) -> None:
page.goto("https://example.com")
context = new_context()
page2 = context.new_page()
# page and page2 are in different contexts

按浏览器跳过测试

🌐 Skip test by browser

test_my_application.py
import pytest

@pytest.mark.skip_browser("firefox")
def test_visit_example(page):
page.goto("https://example.com")
# ...

在特定浏览器上运行

🌐 Run on a specific browser

conftest.py
import pytest

@pytest.mark.only_browser("chromium")
def test_visit_example(page):
page.goto("https://example.com")
# ...

使用自定义浏览器通道(例如 Google Chrome 或 Microsoft Edge)运行

🌐 Run with a custom browser channel like Google Chrome or Microsoft Edge

pytest --browser-channel chrome
test_my_application.py
def test_example(page):
page.goto("https://example.com")

配置 base-url

🌐 Configure base-url

base-url 参数开始Pytest。用 ['pytest-base-url'](https://github.com/pytest-dev/pytest-base-url) 插件来设置配置文件、CLI ARG 或作为 fixture 的基础 URL。

🌐 Start Pytest with the base-url argument. The pytest-base-url plugin is used for that which allows you to set the base url from the config, CLI arg or as a fixture.

pytest --base-url http://localhost:8080
test_my_application.py
def test_visit_example(page):
page.goto("/admin")
# -> Will result in http://localhost:8080/admin

忽略 HTTPS 错误

🌐 Ignore HTTPS errors

conftest.py
import pytest

@pytest.fixture(scope="session")
def browser_context_args(browser_context_args):
return {
**browser_context_args,
"ignore_https_errors": True
}

使用自定义视口大小

🌐 Use custom viewport size

conftest.py
import pytest

@pytest.fixture(scope="session")
def browser_context_args(browser_context_args):
return {
**browser_context_args,
"viewport": {
"width": 1920,
"height": 1080,
}
}

设备模拟 / BrowserContext 选项覆盖

🌐 Device emulation / BrowserContext option overrides

conftest.py
import pytest

@pytest.fixture(scope="session")
def browser_context_args(browser_context_args, playwright):
iphone_11 = playwright.devices['iPhone 11 Pro']
return {
**browser_context_args,
**iphone_11,
}

或者通过 CLI --device="iPhone 11 Pro"

🌐 Or via the CLI --device="iPhone 11 Pro"

连接到远程浏览器

🌐 Connect to remote browsers

conftest.py
import pytest

@pytest.fixture(scope="session")
def connect_options():
return {
"wsEndpoint": "ws://localhost:8080/ws"
}

unittest.TestCase 一起使用

🌐 Using with unittest.TestCase

请参阅以下使用 unittest.TestCase 的示例。这有一个限制,只能指定一个浏览器,并且当指定多个浏览器时不会生成多个浏览器的矩阵。

🌐 See the following example for using it with unittest.TestCase. This has a limitation, that only a single browser can be specified and no matrix of multiple browsers gets generated when specifying multiple.

import pytest
import unittest

from playwright.sync_api import Page


class MyTest(unittest.TestCase):
@pytest.fixture(autouse=True)
def setup(self, page: Page):
self.page = page

def test_foobar(self):
self.page.goto("https://microsoft.com")
self.page.locator("#foobar").click()
assert self.page.evaluate("1 + 1") == 2

调试

🌐 Debugging

与 pdb 一起使用

🌐 Use with pdb

在你的测试代码中使用 breakpoint() 语句来暂停执行并获取一个 pdb REPL。

🌐 Use the breakpoint() statement in your test code to pause execution and get a pdb REPL.

def test_bing_is_working(page):
page.goto("https://bing.com")
breakpoint()
# ...

部署到 CI

🌐 Deploy to CI

查看 CI 提供商指南 将你的测试部署到 CI/CD。

🌐 See the guides for CI providers to deploy your tests to CI/CD.

异步 Fixtures

🌐 Async Fixtures

要使用异步夹具,请安装 pytest-playwright-asyncio

🌐 To use async fixtures, install pytest-playwright-asyncio.

确保你正在使用 pytest-asyncio>=0.26.0 并在你的配置 (pytest.ini/pyproject.toml/setup.cfg) 中设置 asyncio_default_test_loop_scope = session

🌐 Ensure you are using pytest-asyncio>=0.26.0 and set asyncio_default_test_loop_scope = session in your configuration (pytest.ini/pyproject.toml/setup.cfg).

import pytest
from playwright.async_api import Page

@pytest.mark.asyncio(loop_scope="session")
async def test_foo(page: Page):
await page.goto("https://github.com")
# ...