FR: Firebase Auth support for watchOS

[hohteri]

Please add support for Firebase Auth for watchOS apps/targets. Thanks!
Linking to umbrella issue #269 and Firestore for watchOS #4559

[hohteri]

Sign-in with email and password works with changes in hohteri@1eebd57

Also sign-in with email link work if you send fcmToken as parameter (don't know about security implications) and handle the Firebase backend redirection in Firebase Functions

In app:

let fcmToken = result.token
                            let settings = ActionCodeSettings()
                            settings.url = URL(string: "https://yourprojectehere.cloudfunctions.net/signIn?fcmToken=\(fcmToken)")
                            settings.handleCodeInApp = true
                            settings.setIOSBundleID("com.yourpackage.here")
                            settings.setAndroidPackageName("com.yourpackage.here", installIfNotAvailable: true, minimumVersion: nil)
                            
                            Auth.auth().sendSignInLink(toEmail: self.email, actionCodeSettings: settings) { (error) in
                                if let error = error {
                                    NSLog("Signin link sending error: \(error)")
                                } else {
                                    NSLog("Signin link sent")
                                }
                            }

In functions:

exports.signIn = functions.https.onRequest((req, resp) => {
    const ua = req.get("User-Agent")
    // watchOS browser declares itself as an iPhone, this I guess is not an issue as an iPhone would handle the firebase URL Scheme, watchOS does not support URL Schemes
    if (ua.includes("iPhone")) { 
        const payload = {
            notification: {
                title: "Sign in",
                body: "Tap this notification to sign in",
                click_action: "SIGN_IN_CATEGORY"
            },
           data: {
                oobCode: req.query.oobCode,
                mode: req.query.mode,
                apiKey: req.query.apiKey,
                lang: req.query.lang
           }
        }
        return admin.messaging().sendToDevice([req.query.fcmToken], payload).then( res => {
           return resp.send("ok, notif sent")
        })
    } else {
        resp.send("OK, not an apple watch")
    }
})

This however shows a weird open in app screen from Firebase backend, which I guess could be avoided with the below commit and supporting the the notification sending in the Firebase backend natively:

hohteri@946afcb

Finally the sign in is handled in the app:

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
        let content = response.notification.request.content
        switch (content.categoryIdentifier) {
        case "SIGN_IN_CATEGORY":
            if (response.actionIdentifier == "SIGN_IN_ACTION") {
                let link = "https://domain/?oobCode=\(content.userInfo["oobCode"]!)&mode=\(content.userInfo["mode"]!)&apiKey=\(content.userInfo["apiKey"]!)&lang=\(content.userInfo["lang"]!)"
                Auth.auth().signIn(withEmail: "get_user_email_somehow@gmail.com", link: link) { (result, error) in
                    completionHandler()
                }
                return
            }
        default:
            ...
        }
    }

[morganchen12]

Thanks for the exploratory implementation! @renkelvin WDYT?

[paulb777]

@hohteri Thanks! We need a PR with a signed CLA to evaluate the proposed changes.

[hohteri]

@paulb777 afaik Firebase backend is not public code. I would still like to test Sign-In with Apple before doing a PR. The above was more or less conversation opener if the sign with link feature could be implemented as proposed on watchOS.

[paulb777]

@hohteri Yes, the backend is not public code. And we definitely need to do the testing before merging a PR.

However, a PR with a signed CLA is the best way to enable Googlers to participate in a conversation about code.

Hi All,
Is FirebaseAuth now available in watchOS 6+ ?

[paulb777]

Sorry, but we haven't yet finished the testing on #5585 and haven't yet been able to merge the support. We've been swamped with other tasks, but hopefully can get back to this in the next month or so.

[ryanwilson]

This was addressed with #6260 - thanks again for the contribution!