How do I properly call an HTTPs callable function from my app?

Question

I followed some guides and wrote a cloud function. Now I need to call it from within my app. I did the following:

Kotlin code:

class ActivitySignup : AppCompatActivity() {

    private lateinit var functions: FirebaseFunctions
    private lateinit var user: String

    override fun onCreate(savedInstanceState: Bundle?) {
    ...
    functions = Firebase.functions
    ...
    submitbutton.setOnClickListener() {
            Log.e(tag,"Clicked submit")
            userEditTxt = findViewById(R.id.et_user)
            user = userEditTxt.text.toString().trim()

         auth.createUserWithEmailAndPassword(email, password)
            .addOnCompleteListener(this) { task ->
                if (task.isSuccessful) {
                    // Sign in success, update UI with the signed-in user's information
                    Log.i(tag, "User created")

                    functions.getHttpsCallable("addUser")
                    .call(user)
                    .continueWith { task ->
                        // This continuation runs on either success or failure, but if the task
                        // has failed then result will throw an Exception which will be
                        // propagated down.
                        val result = task.result?.data as String
                        Log.e("result", result)
                        result
                    }

                    val intent = Intent(this, ActivityGroups::class.java)
                    startActivity(intent)
                    finish()

                } else {
                    // If sign in fails, display a message to the user.
                    Log.w(tag, "failure", task.exception)
                    Toast.makeText(baseContext, "Authentication failed.",
                        Toast.LENGTH_SHORT).show()
                }

        }

    }

The cloud function in index.ts:

import * as functions from 'firebase-functions';
import * as admin from 'firebase-admin';
admin.initializeApp();

exports.addUser = functions.https.onCall((data, context) => {
  console.log('addUser: ', data.username);

  const username = data.username
  functions.auth.user().onCreate(user => {
    const doc = admin.firestore().collection('users').doc();
    return doc.set({
      createDate: admin.firestore.FieldValue.serverTimestamp(),
      modifiedDate: admin.firestore.FieldValue.serverTimestamp(), 
      username: username,
      email: user.email,    
      stat: 1, //0 = banned, 1 = normal
      uid: user.uid,
      rowpointer: doc.id,
    });
  });

However, there are 2 problems:

1. Android studio is highlighting the "functions" part of Firebase.functions in red. The error is Unresolved reference: functions

2. When I did firebase serve in Visual Studio, I got the following:

• functions[addUser]: http function initialized (http://localhost:5000/APPNAME-cf4da/us-central1/addUser).

i functions: Beginning execution of "addUser"

{"severity":"WARNING","message":"Request has invalid method. GET"}

{"severity":"ERROR","message":"Invalid request, unable to process."}

i functions: Finished "addUser" in ~1s

I'm pretty new to Android dev/cloud functions, so I feel like I'm just making a rookie mistake somewhere...

Answer 1

This nesting makes no sense:

exports.addUser = functions.https.onCall((data, context) => {
  console.log('addUser: ', data.username);

  const username = data.username
  functions.auth.user().onCreate(user => {
    const doc = admin.firestore().collection('users').doc();
    return doc.set({
      createDate: admin.firestore.FieldValue.serverTimestamp(),
      modifiedDate: admin.firestore.FieldValue.serverTimestamp(), 
      username: username,
      email: user.email,    
      stat: 1, //0 = banned, 1 = normal
      uid: user.uid,
      rowpointer: doc.id,
    });
  });

You seem to be trying to register a functions.auth.user().onCreate function inside a functions.https.onCall function, which is not possible. All Cloud Functions need to be top-level exports of your index.js file.

My best guess is that you want to pass information about the just created user from your Android code to the Cloud Function, in which case that should be in the datsa parameter that is passed to onCall(data, context). If you actually "just" want to know the current user, you can also get that from context.auth as shown in documentation on writing and deploying a callable Cloud Function.

This is probably closer, although there may have been more problems in your original code:

exports.addUser = functions.https.onCall((data, context) => {
  console.log('addUser: ', data.username);
  const username = data.username;
  const email = data.email;
  const uid = context.auth.uid; //  get uid from context
  const doc = admin.firestore().collection('users').doc(uid); //  use uid as document ID
  return doc.set({
      createDate: admin.firestore.FieldValue.serverTimestamp(),
      modifiedDate: admin.firestore.FieldValue.serverTimestamp(), 
      username: username,
      email: email,    
      stat: 1, //0 = banned, 1 = normal
      uid: uid
  });
});