Interact with an extension on Firefox

[kilted-andres]

No description provided.

[kilted-andres]

Hi,

I manage to launch the Nightly-browser (Firefox) with my local extension file thanks to your package. Thanks, its great!

Now I am trying to read the UUID of the extension in order to laund the moz-extension://{extension-UUID}/popup.html site of it and test as usual.

I normally read the UUID from this page: about:debugging#/runtime/this-firefox; but playwright hangs waiting for it to load. It is a local page and playwright is waiting a server response that is not comming. The problem is, that I cannot interact with the page and read the content of its elements because of this.

Do you know a workaround to interect with about: pages?
Or better, is there another way to read my extension UUID?

Best wishes,
Andrés

[kilted-andres]

So, I managed to get the UUID from another way. Here the code for it:

`
const page = await context.newPage();
const ffremote = await remote.connect(RDP_PORT);
const response= await ffremote.client.request('listAddons');
console.log(response);

const extension: any = response.addons.find((i: any) => i.name === 'myExtensionName');

if (!extension) throw new Error("no extension loaded");

const match: any = extension.manifestURL.match(/moz-extension:\/\/(.+)\/manifest.json/);

const extensionUUID = match[1];
if (!extensionUUID) throw new Error('extension internal UUID not found');
console.log('extension UUID', extensionUUID);`

Trying to interact with the moz-extension://{extension-UUID}/popup.html is still giving me trouble. Playwright still fails waiting for a "load" event.

[chrmod]

We run into same problems with Playwright timeout on extension page load.

navigating to "moz-extension://3916d385-f277-4b99-af03-868931d9887e/app/templates/onboarding.html", waiting until "load"

[adrienbrault]

You can force a static UUID to be used when testing an extension:

1. Use the browser_specific_settings manifest.json option to define an extension id:

{
  "browser_specific_settings": {
    "gecko": {
      "id": "[email protected]"
    }
  }
}

2. After using withExtension from this package, set extensions.webextensions.uuids using firefoxUserPrefs:

const context = await browserTypeWithExtension.launch({
  firefoxUserPrefs: {
    "extensions.webextensions.uuids": JSON.stringify({
      "[email protected]": "2975768f-5c9f-4941-86e9-c53dfb667d84"
    })
  }
})

[olso-nordsec]

@chrmod problem is that moz-extension:// seems to be privileged page

this lib works if you try to navigate to e.g. https://google.com

i'm looking in about:config for a flag to turn this off

---

update 1

DEBUG=pw:* npx playwright test tests/smoke.spec.ts --project='Firefox'

;5;207m+1s\u001b[0m\n"}}} +0ms
  pw:channel:event {
  pw:channel:event   guid: 'frame@f8a92142e63f0ccf973137c336ecfda2',
  pw:channel:event   method: 'loadstate',
  pw:channel:event   params: { add: 'networkidle' }
  pw:channel:event } +1s
  pw:test:protocol ◀ RECV {"method":"__dispatch__","params":{"method":"stdErr","params":{"text":"  \u001b[30;1mpw:browser \u001b[0m[pid=41441][err] JavaScript warning: resource://gre/modules/UpdateService.sys.mjs, line 3860: unreachable code after return statement \u001b[30m+28s\u001b[0m\n"}}} +0ms
  pw:browser [pid=41441][err] JavaScript warning: resource://gre/modules/UpdateService.sys.mjs, line 3860: unreachable code after return statement +28s
  pw:test:protocol ◀ RECV {"method":"__dispatch__","params":{"method":"stdErr","params":{"text":"  \u001b[30;1mpw:browser \u001b[0m[pid=41441][out] console.error: (new Error(\"Polling for changes failed: The URI is malformed..\", \"resource://services-settings/remote-settings.sys.mjs\", 324)) \u001b[30m+3ms\u001b[0m\n"}}} +0ms
  pw:browser [pid=41441][out] console.error: (new Error("Polling for changes failed: The URI is malformed..", "resource://services-settings/remote-settings.sys.mjs", 324))

it seems that playwright firefox patch might be causing some issues

https://github.com/microsoft/playwright/blob/1277ec99008898cba23c3511d024972e42409963/browser_patches/firefox/patches/bootstrap.diff#L2590

causing https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Errors/Stmt_after_return

---

update 2

but i guess the core issue is this line

https://github.com/microsoft/playwright/blob/1277ec99008898cba23c3511d024972e42409963/browser_patches/firefox/juggler/content/JugglerFrameChild.jsm#L41

[chrmod]

@olso-nordsec thanks for great analysis!

@dgozman can you please explain what's the reason behind https://github.com/microsoft/playwright/blob/1277ec99008898cba23c3511d024972e42409963/browser_patches/firefox/juggler/content/JugglerFrameChild.jsm#L41 ?

Should this issue be moved to under the main playwright repo?

[dgozman]

@chrmod Playwright does not support Firefox extensions, thus the line you linked to.

[chrmod]

@dgozman I do understand that the team does no support the Firefox extension. I'm asking, as perhaps with some changes like removal of guards mentioned we could get some functionality running. Would you be open for partial support if driven by community?

[jochen-testingbot]

Any updates on this? We are also looking into testing the UI of Firefox extensions. Can https://github.com/microsoft/playwright/blob/1277ec99008898cba23c3511d024972e42409963/browser_patches/firefox/juggler/content/JugglerFrameChild.jsm#L41 be removed, would this help to test the extension?

Right now Playwright waits on the page load and is unable to interact with the page.