Chrome 插件

简介

备注

扩展仅在使用持久化上下文启动的 Chrome / Chromium 中有效。使用自定义浏览器参数时请自行承担风险，因为某些参数可能会破坏 Playwright 的功能。

以下代码片段获取位于 ./my-extension 的 Manifest v2 扩展的后台页面。

请注意使用了 chromium 通道，这允许在无头模式下运行扩展。或者，你也可以在有界面模式下启动浏览器。

同步

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,
        channel="chromium",
        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]

    # 测试后台页面，就像测试其他页面一样。
    context.close()


with sync_playwright() as playwright:
    run(playwright)

异步

import asyncio
from playwright.async_api import async_playwright, Playwright

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


async def run(playwright: Playwright):
    context = await playwright.chromium.launch_persistent_context(
        user_data_dir,
        channel="chromium",
        args=[
            f"--disable-extensions-except={path_to_extension}",
            f"--load-extension={path_to_extension}",
        ],
    )

    if len(context.background_pages) == 0:
        background_page = await context.wait_for_event('backgroundpage')
    else:
        background_page = context.background_pages[0]

    # 测试后台页面，就像测试其他页面一样。
    await context.close()


async def main():
    async with async_playwright() as playwright:
        await run(playwright)


asyncio.run(main())

测试

要在运行测试时加载扩展，你可以使用测试夹具来设置上下文。你还可以动态检索扩展 ID 并使用它来加载和测试弹出页面。

请注意使用了 chromium 通道，这允许在无头模式下运行扩展。或者，你可以在有界面模式下启动浏览器。

首先，添加将加载扩展的夹具：

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(
        "",
        channel="chromium",
        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

然后在测试中使用这些夹具：

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")