Flutter App Hangs on Sign-In After Firebase Operation

Below is a list of suggestions and a refactored version of your code that may help you diagnose and resolve the hanging issue.

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Suggestions

• Avoid Mixing async/await with .then:
  Mixing await with .then can sometimes lead to unexpected behavior. It's often clearer (and easier to debug) if you consistently use async/await with try/catch.

• Add Error Handling:
  Wrap your asynchronous calls inside try/catch blocks. This way, if an error is thrown (for example, due to a misconfigured Firebase rule or network issue), you can see the error rather than just having the UI hang.

• Debug the Firebase Calls:

  • Confirm that your Firebase project is correctly set up and that Firestore rules permit the write.
  • Check if the image upload function (addImageToFirebaseStorage) might be causing the block. Ensure that if you're calling it, any asynchronous operation inside is handled properly.

• Logging:
  Add logging (or snackbar messages) before/after each Firebase call to narrow down which call is blocking your UI.

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Refactored Code Example

Below is an example of how you could refactor your signUp method to use async/await exclusively and include error handling:

DARTCopied
class UserViewModel {
  Future<void> signUp(
    String email,
    String password,
    String firstName,
    String lastName,
    String city,
    String country,
    String bio,
    dynamic imageFileOfUser, // replace 'dynamic' with your expected type (e.g., File)
  ) async {
    Get.snackbar("Please wait", "We are creating an account for you");

    try {
      // Create user with Firebase Authentication
      UserCredential result = await FirebaseAuth.instance
          .createUserWithEmailAndPassword(email: email, password: password);
      String currentUserId = result.user!.uid;
      
      // Store user information in your App's state
      AppConstants.currentUser.id = currentUserId;
      AppConstants.currentUser.firstName = firstName;
      AppConstants.currentUser.lastName = lastName;
      AppConstants.currentUser.city = city;
      AppConstants.currentUser.country = country;
      AppConstants.currentUser.bio = bio;
      AppConstants.currentUser.email = email;
      AppConstants.currentUser.password = password;
      
      // Save user data to Firestore
      await saveUserToFirestore(
        bio,
        city,
        country,
        email,
        firstName,
        lastName,
        currentUserId,
      );
      
      // Optionally, await image upload to Firebase Storage
      await addImageToFirebaseStorage(imageFileOfUser, currentUserId);

      Get.snackbar("Congratulations", "Your account has been created");
    } catch (e) {
      // Display errors to the user
      Get.snackbar("Error", e.toString());
      print("Error during sign up: $e");
    }
  }
}

Future<void> saveUserToFirestore(
  bio,
  city,
  country,
  email,
  firstName,
  lastName,
  id,
) async {
  Map<String, dynamic> dataMap = {
    "bio": bio,
    "city": city,
    "country": country,
    "email": email,
    "firstName": firstName,
    "lastName": lastName,
    "isHost": false,
    "myPostingIDs": [],
    "savedPostingIDs": [],
    "earnings": 0,
  };

  await FirebaseFirestore.instance.collection("users").doc(id).set(dataMap);
}

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Things to Verify

• Firebase Configuration:
  Ensure that your Firebase project is set up correctly (including proper API keys, initialization of Firebase in your app, etc.).

• Firestore Rules:
  Verify that Firestore security rules allow writes to the "users" collection for authenticated users.

• Image Upload Function:
  Check the implementation of addImageToFirebaseStorage to ensure it’s correctly handling asynchronous operations.

• Internet Connectivity:
  Confirm that your testing device/simulator has an active internet connection.

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Try this refactored code and check the logs/banner messages when running the app. These changes should help you pinpoint where the hang is occurring and address the issue.