介绍

注意

插件仅在以持久化上下文启动的 Chrome/Chromium 浏览器中工作。请谨慎使用自定义浏览器参数，因为其中一些可能会破坏 Playwright 的功能。

以下是获取位于 ./my-extension 的 Manifest v2 插件背景页面句柄的代码示例。

from playwright.sync_api import sync_playwright, Playwright

path_to_extension = "./my-extension"
user_data_dir = "/tmp/test-user-data-dir"


def run(playwright: Playwright):
    context = playwright.chromium.launch_persistent_context(
        user_data_dir,
        headless=False,
        args=[
            f"--disable-extensions-except={path_to_extension}",
            f"--load-extension={path_to_extension}",
        ],
    )
    if len(context.background_pages) == 0:
        background_page = context.wait_for_event('backgroundpage')
    else:
        background_page = context.background_pages[0]

    # Test the background page as you would any other page.
    context.close()


with sync_playwright() as playwright:
    run(playwright)

测试

为了在运行测试时加载扩展，你可以使用测试夹具（fixture）来设置上下文。此外，你还可以动态地检索扩展ID，并使用它来加载和测试例如弹出页面等。

首先，添加将加载扩展的测试夹具（fixtures）。

conftest.py
from typing import Generator
from pathlib import Path
from playwright.sync_api import Playwright, BrowserContext
import pytest


@pytest.fixture()
def context(playwright: Playwright) -> Generator[BrowserContext, None, None]:
    path_to_extension = Path(__file__).parent.joinpath("my-extension")
    context = playwright.chromium.launch_persistent_context(
        "",
        headless=False,
        args=[
            f"--disable-extensions-except={path_to_extension}",
            f"--load-extension={path_to_extension}",
        ],
    )
    yield context
    context.close()


@pytest.fixture()
def extension_id(context) -> Generator[str, None, None]:
    # for manifest v2:
    # background = context.background_pages[0]
    # if not background:
    #     background = context.wait_for_event("backgroundpage")

    # for manifest v3:
    background = context.service_workers[0]
    if not background:
        background = context.wait_for_event("serviceworker")

    extension_id = background.url.split("/")[2]
    yield extension_id

然后在测试中使用

test_foo.py
from playwright.sync_api import expect, Page


def test_example_test(page: Page) -> None:
    page.goto("https://example.com")
    expect(page.locator("body")).to_contain_text("Changed by my-extension")


def test_popup_page(page: Page, extension_id: str) -> None:
    page.goto(f"chrome-extension://{extension_id}/popup.html")
    expect(page.locator("body")).to_have_text("my-extension popup")

无头模式（Headless Mode）

警告

--headless=new 模式并不是 Playwright 官方支持的功能，并且可能会导致意外的行为。

在 Playwright 中，Chrome 的默认无头模式并不支持 Chrome 扩展。为了克服这一限制，你可以通过以下代码以新的无头模式运行 Chrome 的持久化上下文（persistent context）：

conftest.py
path_to_extension = Path(__file__).parent.joinpath("my-extension")
context = playwright.chromium.launch_persistent_context(
    "",
    headless=False,
    args=[
        "--headless=new",
        f"--disable-extensions-except={path_to_extension}", # 禁用 Chrome 浏览器中的所有扩展，除了指定路径（{path_to_extension}）下的扩展。
        f"--load-extension={path_to_extension}", # 指定 Chrome 浏览器启动时应该加载的扩展的路径
    ],
)