[google_sign_in] Add implementations of requestScopes.

[emerssso]

Description

Adds implementation for requestScopes method introduced to the plugin interface in #2547.

Recreated since I messed up rebasing after first PR.

Related Issues

• Allow requesting additional scopes via the google_sign_in plugin flutter#50208

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[ditman]

The web part of this, looks good to me! What's the use case here? Requesting a minimal set of scopes at first, and then if the user interacts further in the app request some more?

[emerssso]

That's the primary one (basically approach scopes the same as other permissions). This way, we ask for permission to sensitive data in the context where it makes sense.

The other is to handle adding scopes as part of an app update. We see issues adding new scopes to the constructor when a user has signed in before an update that adds a scope (issues vary by platform). This way, we won't have to sign users out when we add scopes.

[ditman]

We see issues adding new scopes to the constructor when a user has signed in before an update that adds a scope

This sounds very interesting. I'm not sure if this is documented anywhere in the Google Sign In API or similar, but it'd probably be worth a medium blog post or similar! We can help you publish an article about this progressive approach to scopes, if you're interested in writing it!

[emerssso]

if you're interested in writing it!

It does sound like something worth writing, I'll ping you about it offline.

[cyanglaz]

iOS and Android part looks good. Could we possibly add JUnit tests and XCTests?

[emerssso]

iOS and Android part looks good. Could we possibly add JUnit tests and XCTests?

@cyanglaz, Happy to, I just couldn't find any existing ones for this plugin (and couldn't figure out how to add some easily). Do they live somewhere else and I just missed them?

[ditman]

PS @emerssso, a g3 issue just prompted this PR, it'll cause some (easy) conflicts in the pubspec + changelog of your _web changes. My apologies!

[emerssso]

@ditman, No problem, thanks for the heads up!

[cyanglaz]

GLTM on mobile