firebase-ios-sdk/FirebaseAuth/Sources/Swift/Auth/Auth+AsyncStream.swift

// Copyright 2023 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import Foundation

@available(iOS 13, tvOS 13, macOS 10.15, macCatalyst 13, watchOS 7, *)
extension Auth {
  public func authDidChangeSequence() -> AsyncStream<User?> {
    .init { continuation in
      let listener = addStateDidChangeListener { auth, user in
        continuation.yield(user)
      }

      continuation.onTermination =  { @Sendable _ in
        self.removeStateDidChangeListener(listener)
      }
    }
  }
}