Flutter-Firebase：未處理的異常：[firebase_functions/internal] 響應無效 JSON object

Question

我正在嘗試將可調用的 function 添加到我的應用程序，但我得到的是未處理的異常：[firebase_functions/internal] 響應無效 JSON ZA8CFDE6331BD59EB2AC96F8911BB4。 我嘗試了另一個非常簡單的 function，結果總是一樣的。 這是 function：

const functions = require("firebase-functions");

exports.sendMessage = functions.https.onCall((data, context) => {
  return ["Apple", "Banana", "Cherry", "Date"];
});

這是電話：

Future<void> checkCallable() async {
    debugPrint((await FirebaseFunctions.instance.httpsCallable('sendMessage').call()).data);
  }

最后是錯誤：

E/flutter (26536): [ERROR:flutter/lib/ui/ui_dart_state.cc(198)] Unhandled Exception: [firebase_functions/internal] Response is not valid JSON object.
E/flutter (26536): 
E/flutter (26536): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
E/flutter (26536): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:167:18)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #2      MethodChannelHttpsCallable.call (package:cloud_functions_platform_interface/src/method_channel/method_channel_https_callable.dart:23:24)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #3      HttpsCallable.call (package:cloud_functions/src/https_callable.dart:49:37)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #4      _MyHomePageState.checkCallable (package:league_tracker/main.dart:79:17)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): 
E/flutter (26536): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
E/flutter (26536): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:167:18)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #2      MethodChannelHttpsCallable.call (package:cloud_functions_platform_interface/src/method_channel/method_channel_https_callable.dart:23:24)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #3      HttpsCallable.call (package:cloud_functions/src/https_callable.dart:49:37)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #4      _MyHomePageState.checkCallable (package:league_tracker/main.dart:79:17)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): 
I/flutter (26536): Got null accent color.
D/InputTransport(26536): Input channel destroyed: 'ClientS', fd=146
E/flutter (26536): [ERROR:flutter/shell/common/shell.cc(93)] Dart Unhandled Exception: [firebase_functions/internal] Response is not valid JSON object.
E/flutter (26536): 
E/flutter (26536): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
E/flutter (26536): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:167:18)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #2      MethodChannelHttpsCallable.call (package:cloud_functions_platform_interface/src/method_channel/method_channel_https_callable.dart:23:24)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #3      HttpsCallable.call (package:cloud_functions/src/https_callable.dart:49:37)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #4      _MyHomePageState.checkCallable (package:league_tracker/main.dart:79:17)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): , stack trace: #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:607:7)
E/flutter (26536): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:167:18)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #2      MethodChannelHttpsCallable.call (package:cloud_functions_platform_interface/src/method_channel/method_channel_https_callable.dart:23:24)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #3      HttpsCallable.call (package:cloud_functions/src/https_callable.dart:49:37)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): #4      _MyHomePageState.checkCallable (package:league_tracker/main.dart:79:17)
E/flutter (26536): <asynchronous suspension>
E/flutter (26536): 

編輯：在 function 我也嘗試返回類似：

return {message: text};

或者

return "text";

Answer 1

響應必須是 JSON object，試試這樣的：

exports.sendMessage = functions.https.onCall((data, context) => {
  return {result: ["Apple", "Banana", "Cherry", "Date"]};
});

有關詳細信息，請參閱響應正文。