Audit usage of navigator userAgent, appVersion, and platform

[jessegreenberg]

Putting in phet-core because that is where platorm.js lives, but there are usages of these in a few places in the project.

@Nancy-Salpepi noticed this warning while testing involving a reduction in the amount of information available in the User Agent string.

Here is information from Chrome about the changes and timeline: https://blog.chromium.org/2021/05/update-on-user-agent-string-reduction.html

[jessegreenberg]

Just noting the parts from https://blog.chromium.org/2021/05/update-on-user-agent-string-reduction.html that I found important:

Regarding timeline:

no User-Agent string changes will be coming to the stable channel of Chrome in 2021.

Regarding compatibility:

Once this is complete, you will still be able to reliably get the browser major version, platform name, and distinguish between desktop and mobile (or tablet), solely from the User-Agent string. For more advanced use cases, you should migrate to the User Agent Client Hints API.

Our plan was designed with backwards compatibility in mind, and while any changes to the User Agent string need to be managed carefully, we expect minimal friction for developers as we roll this out (i.e., existing parsers should continue to operate as expected).

If your site, service, library or application relies on certain bits of information being present in the User Agent string such as Chrome minor version, OS version number, or Android device model, you will need to begin the migration to use the User Agent Client Hints API instead.

If you don’t require any of these, then no changes are required and things should continue to operate as they have to date.

I don't see anything in platform.js about Chrome version number, OS version number, or Android device model. So we may be OK with this change. But adding to developer meeting to review with the team and check if anything should be done.

[samreid]

I noted that there are numerous usages of navigator.userAgent outside of platform.js as well. A few usages of navigator.platform elsewhere.

[jessegreenberg]

Discussed 8/19/21 at developer meeting:

It doesn't seem like we are using the features of the user agent strings that are being changed. According to https://blog.chromium.org/2021/05/update-on-user-agent-string-reduction.html there will be a trail version that we can test before the change goes live. When that is ready we can do some testing to make sure everything is still running OK.

@jonathanolson mentioned there might be some impacts on yotta but there likely isn't much we can do about it.

We added a reminder to the dev meeting doc to see if a Trail version of chrome with this change is ready yet since there aren't any dates listed in https://blog.chromium.org/2021/05/update-on-user-agent-string-reduction.html for when that will happen.

[zepumph]

Bringing back up to dev meeting.

[jessegreenberg]

According to https://blog.chromium.org/2021/09/user-agent-reduction-origin-trial-and-dates.html and https://developer.chrome.com/blog/user-agent-reduction-origin-trial/

We can register for a trail version with user agent reduction here: https://developer.chrome.com/origintrials/#/view_trial/-7123568710593282047

We have until April 19th 2022 to register.

[zepumph]

We We feel like this is worthy of discussion, but want to wait for @jonathanolson to be present. Before next week we would like to register in the link above, thanks for doing that @jessegreenberg.

MK sees that chrome's message recommends navigator.userAgentData, but @samreid mentioned that it is not broadly supported by browsers.

We will discuss next week!

[jessegreenberg]

We do NOT want to register PhET for a trail, apparently that impacts all users of our origin!

When Chrome offers an origin trial for a feature, you can register for the trial to enable the feature for all users on your origin, without requiring them to toggle any flags or switch to an alternative build of Chrome (though they may need to upgrade).

But I think we can register localhost and use that to test locally.