錯誤解析錯誤：將功能部署到Firebase時，無效的正則表達式標志

Question

使用firebase為我的android聊天應用程序項目使用node.js創建推送通知。 當我在通知功能上部署Firebase時，出現了一些錯誤。

這是我在38:11和39:16的index.js ****這是我的index.js ****

'use strict'

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase);

exports.sendNotification = functions.database.ref('/notification/{user_id}/{notification_id}').onWrite(event => {

const user_id = event.params.user_id;
const notification = event.params.notification;

console.log("The User Id is : ",user_id);

if(!event.data.val()){

return console.log('A Notification has been deleted from database : ', notification_id);
}

const fromUser = admin.database().ref(/notification/${user_id}/{notification_id}).once(value);
return fromUser.then(fromUserResult => {

    const from_user_id = fromUserResult.val().from;
    console.log('You have new notification from : ', from_user_id);

    const userQuery = admin.database().ref(`/Users/${user_id}/${notification_id}`).once('value');
    return userQuery.then(userResult => {

        const userName = userResult.val();
        const deviceToken = admin.database().ref(`/Users/${user_id}/device_token`).once('value');

        return deviceToken.then (result => {

          const token_id = result.val();

          const payload = {
            notification : {

              title : "Friend Request",
              body : `${userName} has sent you request`,
              icon : "default"
            }
          };

          return admin.messaging().sendToDevice(token_id , payload);
        });
  });
});
});
**The cmd give me following result**


C:\Users\Ouneeb Ur Rehman\Desktop\notification function\functions\index.js
  19:40  error  Parsing error: Invalid regular expression flag

✖ 1 problem (1 error, 0 warnings)

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.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\Ouneeb Ur Rehman\AppData\Roaming\npm-cache\_logs\2018-05-23T11_05_23_181Z-debug.log

Error: functions predeploy error: Command terminated with non-zero exit 
I try install and uninstall npn and firebase tools but alls goes to vane 

我獲得了Firebase令牌ID並存儲在數據庫中，我是Node JS的新手，無法在此處輸入圖片描述 Plz任何人都可以提供幫助

這是我的通知數據庫sinpit

Answer 1

您忘記了第19行的引號（應該使用簡單的引號： ' ）。 Firebase數據庫需要一個字符串，而不是正則表達式。 （請參閱： 參考文檔 ）

第19行應為：

const fromUser = admin.database().ref('/notification/${user_id}/{notification_id}').once(value);

請注意，Javascript正則表達式可以采用以下形式：

/pattern/replacement/flags

這就是為什么elint警告您有關無效的正則表達式標志的原因。