[BUG] Firefox does not launch with executablePath set to Firefox inside Applications folder

[mukunduashok]

Context:

• Playwright Version: 1.1.1
• Operating System: Mac v10.15.4
• Node version: 10.20.1
• Browser: Firefox v77.0.1 / Firefox Developer Edition v78b8
• Extra: Works with inbuilt Firefox. Fails to resolve only when executablePath is provided with Firefox path inside Applications folder

Code Snippet

const {
    firefox
} = require("playwright");

const browser = firefox.launch({
    headless: false,
    executablePath: "/Applications/Firefox\ Developer\ Edition.app/Contents/MacOS/firefox"
}).then((value) => {
    console.log("Browser context is ", value);
    return value
}).catch((err) => console.log("Browser launch error", err));

Expected Output: The value of browser should resolve to firefox browser instance
Actual Output: Below error is received
Browser launch error { TimeoutError: Timeout 30000ms exceeded during firefox.launch. =================== firefox.launch logs =================== <launching> /Applications/Firefox Developer Edition.app/Contents/MacOS/firefox -no-remote -wait-for-browser -foreground -profile /var/folders/w6/lntvmx0536z_xm541_0d3c_9htfqbf/T/playwright_firefoxdev_profile-8xdVsI -juggler 0 -silent <launched> pid=36633 ============================================================ Note: use DEBUG=pw:api environment variable and rerun to capture Playwright logs. at ProgressController.run (/Users/ashok_mb/Documents/xBP/Learner/playwright_spike/node_modules/playwright/lib/progress.js:72:30) at Object.runAbortableTask (/Users/ashok_mb/Documents/xBP/Learner/playwright_spike/node_modules/playwright/lib/progress.js:24:23) at Firefox.launch (/Users/ashok_mb/Documents/xBP/Learner/playwright_spike/node_modules/playwright/lib/server/browserType.js:61:42) at Object.<anonymous> (/Users/ashok_mb/Documents/xBP/Learner/playwright_spike/src/sample.js:5:25) at Module._compile (internal/modules/cjs/loader.js:778:30) at Object.Module._extensions..js (internal/modules/cjs/loader.js:789:10) at Module.load (internal/modules/cjs/loader.js:653:32) at tryModuleLoad (internal/modules/cjs/loader.js:593:12) at Function.Module._load (internal/modules/cjs/loader.js:585:3) at Function.Module.runMain (internal/modules/cjs/loader.js:831:12) name: 'TimeoutError' }

Note:

1. The browser is launched, but we received the timeout error after 30000ms.
2. If I remove "executablePath", the inbuilt firefox launches and resolves.

Kindly let me know if I'm doing anything wrong. Thanks

[mxschmitt]

Hi, what is the reason that you want to use your own Firefox for Playwright tests?
The reason why it's not working is because Playwright uses a custom patched Firefox version (which is in the end the same as normal Firefox except newer and slightly modified to include better bindings to automate it).

[mukunduashok]

@mxschmitt Thanks for the immediate response.

There is no special reason to test with actual released or beta Firefox. We've been using the standards of running the suite against the different versions of Firefox Developer Edition.

I can try out with inbuilt Firefox to start with. Ultimately the expectations would be to run in the actual Firefox. Doesn't playwright support the nightly, beta and released version of Firefox ?

Please help!

[mxschmitt]

I can try out with inbuilt Firefox to start with. Ultimately the expectations would be to run in actually Firefox. Doesn't playwright support the nightly, beta and released version of Firefox ?

For Chromium/Chrome, you could potentially use the latest Canary version which would work with Playwright. But for WebKit and Firefox not, because these browsers were customised (patched) during the build and contain by that special APIs, so that Playwright can interact and control them better. Normal Firefox / WebKit versions, also the latest beta ones, don't contain them yet.

There are plans to push these changes upstream which are currently already on-going but it will probably take a few months.

[mukunduashok]

Ok Nice. Got it. Thanks much @mxschmitt

[arjunattam]

Assigning myself to cover this in our docs. Thanks @mukunduashok and @mxschmitt

[Sandeepisebauz]

Is this feature fixed, I still notice this issue on playwright version 1.22, when I try to use the executable path of the installed firefox path, which is at a higher version (100.0.1) when compared to playwright bundled Firefox version 99.0.1