Question

我正在尝试为我的应用使用firebase推送通知服务。为此，我在我的应用程序中设置了firebase推送通知依赖项，并且还安装了node.js和firebase工具。当我在目录上使用firebase部署来部署函数时，我得到了这个错误

40:14  warning  Avoid nesting promises                      promise/no-
nesting
41:25  error    Each then() should return a value or throw  promise/always-
return

✖ 2 problems (1 error, 1 warning)

npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! functions@ lint: `eslint .`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the functions@ lint script.
npm ERR! This is probably not a problem with npm. There is likely additional 
logging output above.

这是index.js文件

＆＃13;

'use strict'


const functions = require('firebase-functions');
const admin = require ('firebase-admin');
admin.initializeApp(functions.config().firebase);

exports.sendNotification = functions.database.ref('/Notifications/{receiver_id}/{notification_id}')
       .onWrite(event => 
	   {
		   const receiver_id = event.params.receiver_id;
		   
		   const notification_id = event.params.notification_id;
		   
		   console.log('We have a notification to send to : ', receiver_id);
		   
		   if(!event.data.val()) 
		   {
			   return console.log('A notification has been deleted from the database : ', notification_id);
		   }
		   
		   
		   const deviceToken = admin.database().ref(`/Users/${receiver_id}/device_token`).once('value');
		   
		   
		   return deviceToken.then(response => 
		   {
			   const token_id = result.val();
			   
			   const payload = 
			   {
				   notification: 
				   {
					   title: "Friend Request",
					   body: "You have a new friend request",
					   icon: "default"
				   }
			   };
			   
			   return admin.messaging().sendToDevice(token_id, payload)
			               .then(response => 
						   {
							   console.log('This was the notification feature');
						   });
	        });  	  
       });

＆＃13;

我该如何解决这个问题？我的朋友使用相同的代码，上传成功没有错误

Answer 1

来自ESLint的错误消息是：

41:25  error    Each then() should return a value or throw  promise/always-return

它抱怨的代码是：

                       .then(response => 
                       {
                           console.log('This was the notification feature');
                       });

消息是每个then（）方法回调都应该返回一个值或抛出异常。如果您只是在日志后的回调中return null，这可能会有所帮助。

您还有关于嵌套承诺的警告。你的代码更可读，不在另一个（）中使用then（）。您可以简单地将它们相互链接在同一级别以获得相同的效果。

部署firebase推送通知功能时出错

1 个答案: