更新GoogleSignIn后报错：GIDSignInResult无authentication成员

问题原因 #

GoogleSignIn 6.0及以上版本重构了API，原GIDSignInResult的authentication属性被移除，相关认证信息需从GIDSignInResult包含的GIDGoogleUser实例中直接获取。

修复后的代码 #

func googleSignInAction(){
    guard let clientID = FirebaseApp.app()?.options.clientID else { return }
    let config = GIDConfiguration(clientID: clientID)
    
    GIDSignIn.sharedInstance.signIn(withPresenting: self) { signInResult, error in
        if let error = error {
            print("There is an error signing the user in ==> \(error)")
            return
        }

        // 从返回结果中获取Google用户实例及认证令牌
        guard let googleUser = signInResult?.user,
              let idToken = googleUser.idToken?.tokenString,
              let accessToken = googleUser.accessToken.tokenString else {
            return
        }
        
        let credential = GoogleAuthProvider.credential(withIDToken: idToken, accessToken: accessToken)

        Auth.auth().signIn(with: credential) { authResult, error in
            if error != nil {
                print(error)
            } else {
                self.email = authResult?.user.email
                self.photoURL = authResult?.user.photoURL?.absoluteString
                self.checkIfUserAccountExists()
            }
        }
    }
}

关键修改说明 #

• 回调参数user重命名为signInResult，避免与内部的Google用户实例混淆
• 通过signInResult?.user获取GIDGoogleUser实例
• 从googleUser.idToken?.tokenString提取ID Token字符串
• 从googleUser.accessToken.tokenString提取Access Token字符串

内容的提问来源于stack exchange，提问作者Vandal