teams.microsoft.com - Option to join a meeting on web not available

[setzor]

URL: https://teams.microsoft.com/dl/launcher/launcher.html?url=%2f_%23%2fl%2fmeetup-join%2f19%3ameeting_MDY1YzgxYzQtOTk5ZC00NjQ2LTgzMmYtZmZiOTEwYzkzYTIz%40thread.v2%2f0%3fcontext%3d%257b%2522Tid%2522%253a%2522e4ba15d0-7fe2-4bd4-a3ef-a97a4378231e%2522%252c%2522Oid%2522%253a%2522af3a35c4-74b5-4418-890e-ff067dde6e45%2522%257d%26anon%3dtrue&type=meetup-join&deeplinkId=f1f9585b-750f-4166-a73a-5c6d096a4330&directDl=true&msLaunch=true&enableMobilePage=true&suppressPrompt=true

Browser / Version: Firefox 68.0
Operating System: Windows 10
Tested Another Browser: Yes

Problem type: Site is not usable
Description: Site allows joining meetings in Chrome, in Firefox it forces you to download the app to join the meeting.
Steps to Reproduce:
Click link to join meeting. Attendees using Chrome can join the meeting via browser, Firefox users need to download teams app

Browser Configuration

• None

From webcompat.com with ❤️

[cipriansv]

Thanks for the report, @setzor.
I was indeed able to reproduce the issue. You are forced to download the app on Firefox while on Chrome you also have the option to continue on the web.

Tested with:
Browser / Version: Firefox Nightly 70.0a1 (2019-08-15), Chrome 76.0.3809.100
Operating System: Windows 10 Pro

This is the web page displayed in Firefox Nightly:

And this is the web page displayed in Chrome:

[wisniewskit]

If I spoof as Chrome, I can get past that page, but I get stuck at a "please allow so others can see or hear you in the meeting" page, even when I've allowed access to my mic:

2019-08-16T20:07:55.351Z callingAgents: calling-stack [JS.TsCalling.MediaAgent] ffffffff: MA/DeviceManager/PermissionManager Error querying permissions for microphone: TypeError: 'name' member of PermissionDescriptor 'microphone' is not a valid value for enumeration PermissionName. angular.min.js:112:472

So they're relying on the experimental Permissions API to detect microphone support, which Firefox doesn't support yet. Based on the related Mozilla standards position issue on the subject, this is because of privacy concerns which have not yet been resolved.

Microsoft Teams could likely fall back on using getUserMedia to effectively query the user for permissions, but it appears their design is Chromium-specific for now.

[wisniewskit]

Yes, I've confirmed that if I spoof as Chrome and spoof the permissions API to get past that point, I can to a page saying "Hey test, someone in the meeting should let you in soon". I haven't tested further than that, but I still see weird errors in the console like this one:

2019-08-16T21:33:28.877Z callingService: Failed to unmuteMicrophone: unmuteMicrophone is not implemented angular.min.js:112:472

To me this implies that they might be designing to Chromium's non-standard WebRTC stack, which could mean further issues. I think our best bet would be to contact the Teams folks and see what they would need before Teams works with Firefox.

[adamopenweb]

I think this is a duplicate of #25070

[lock]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue at https://webcompat.com/issues/new if you are experiencing a similar problem.