playwright-webextext

This extension library enables loading firefox add-ons and chromium extensions from the local filesystem for [playwright][].

!Screenshot

Install

Install by your package manager

``console
$ npm install --save playwright-webextext # npm
$ yarn add playwright-webextext # yarn
$ pnpm add playwright-webextext # pnpm
`

API

$3

The method provides a custom browser that loads temporary extensions from the local filesystem.

#### Usage

`typescript
import { firefox, chromium } from "playwright";
import { withExtension } from "playwright-webextext";

const launchFirefox = async () => {
const browserTypeWithExtension = withExtension(
firefox, // base browser type
"path/to/your/extensions", // local directory containing manifest.json
);
// launch a browser
const browser = await browserTypeWithExtension.launch();

const page = await browser.newPage();
await page.goto("https://example.com/");
};

const launchChromium = async () => {
const browserTypeWithExtension = withExtension(
chromium, // base browser type
"path/to/your/extensions",
);

// chromium extensions works only in headed browsers with persistent contexts
const browser = await browserTypeWithExtension.launchPersistentContext("", {
headless: false,
});

const page = await browser.newPage();
await page.goto("https://example.com/");
};

launchFirefox();
launchChromium();
`

$3

The method provides custom fixtures that enable browsers to load add-ons and extensions.

#### Usage

`typescript
import { createFixture } from "playwright-webextext";

const { test, expect } = createFixture("path/to/your/extensions");

test("should launch browser with extensions", async ({ page }) => {
await page.goto("https://example.com/");

// ...
});
`

Manifest v3 support

The playwright-webextext does not fully support manifest v3 on Firefox.
Firefox asks users to allow loading content scripts since Manifest v3.

!Prompt to allow loading content scripts

Basically, the user should allow the permission on the about:addon page
manually. The playwright-webextext overrides the permission of the add-on to
allow loading content scripts before launching the browser.

This override works when the add-on has the
browser_specific_settings.gecko.id property in
the manifest.json:

`json
{
"browser_specific_settings": {
"gecko": {
"id": "webextext-examples@i-beam.org"
}
}
}
`

and it's necessary to launch with persistent context, using launchPersistentContext().

[firefox_gecko_properties]: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/browser_specific_settings#firefox_gecko_properties

How does it work

$3

The playwright introduces a way to install chrome extensions in the document. Chromium supports installing extensions via [command-line options][chrome-launch-switches]. The playwright-webextext launches a chromium browser with command-line options with extension paths. See the following document for more details:

- Chrome Extensions | Playwright

Note that using chrome extensions has two limitations: 1) the browser should run on headed mode, and 2) you should launch the browser with a persistent context (launchPersistentContext()`).

[chrome-launch-switches]: https://sites.google.com/site/chromeappupdates/launch-switches

$3

Firefox provides a remote debugging server to control the browser via a [remote debugging protocol][]. This protocol also enables installing a temporary add-on. The playwright-webextext installs add-ons by this protocol.

[remote debugging protocol]: https://firefox-source-docs.mozilla.org/devtools/backend/protocol.html

LICENSE

MIT

[playwright]: https://playwright.dev/