eslint throws error

Question

i am new android beginner and try to deploy firebase functions but show some error how to solve this problem plz help me.

Firebase database structure

User Table

Users
- user_id
  - device_token : user_device_token
  - Name : user_name

Notification Table

notifications
- to_user_id
  - notification_id
    - from : from_user_id

Error

Index.js

'use strict'

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


/*
 * 'OnWrite' works as 'addValueEventListener' for android. It will fire the function
 * everytime there is some item added, removed or changed from the provided 'database.ref'
 * 'sendNotification' is the name of the function, which can be changed according to
 * your requirement
 */

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


	  /*
	   * You can store values as variables from the 'database.ref'
	   * Just like here, I've done for 'user_id' and 'notification'
	   */

	  const user_id = event.params.user_id;
	  const notification_id = event.params.notification_id;

	  console.log('We have a notification from : ', user_id);

	  /*
	   * Stops proceeding to the rest of the function if the entry is deleted from database.
	   * If you want to work with what should happen when an entry is deleted, you can replace the
	   * line from "return console.log.... "
	   */

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

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

		}

	  /*
	   * 'fromUser' query retreives the ID of the user who sent the notification
	   */

	  const fromUser = admin.database().ref(`/notifications/${user_id}/${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);

			/*
			 * The we run two queries at a time using Firebase 'Promise'.
			 * One to get the name of the user who sent the notification
			 * another one to get the devicetoken to the device we want to send notification to
			 */

			const userQuery = admin.database().ref(`/Users/${from_user_id}/Name`).once('value');
			const deviceToken = admin.database().ref(`/Users/${user_id}/device_token`).once('value');

			return Promise.all([userQuery, deviceToken]).then(result => {

			  const userName = result[0].val();
			  const token_id = result[1].val();

			  /*
			   * We are creating a 'payload' to create a notification to be sent.
			   */

			  const payload = {
					notification: {
					  title : "New Friend Request",
					  body: `${userName} has sent you request`,
					  icon: "default",
					
					}
				};

			  /*
			   * Then using admin.messaging() we are sending the payload notification to the token_id of
			   * the device we retreived.
			   */

				  return admin.messaging().sendToDevice(token_id, payload).then(response => {

						console.log('This was the notification Feature');

					});

			});

		});

	});

**cmd show error **

C:\Users\TahirAliAwan\Desktop\Function>firebase deploy === Deploying to 'videochat-96f75'... i deploying functions Running command: npm --prefix %RESOURCE_DIR% run lint functions@ lint C:\Users\TahirAliAwan\Desktop\Function\functions eslint . C:\Users\TahirAliAwan\Desktop\Function\functions\index.js 61:11 warning Avoid nesting promises promise/no-nesting 84:14 warning Avoid nesting promises promise/no-nesting 84:69 error Each then() should return a value or throw promise/always-return ✖ 3 problems (1 error, 2 warnings) npm ERR! Windows_NT 10.0.10586 npm ERR! argv "C:\Program Files\nodejs\node.exe" "C:\Program Files\nodejs\node_modules\npm\bin\npm-cli.js" "--prefix" "C:\Users\TahirAliAwan\Desktop\Function\functions" "run" "lint" npm ERR! node v6.11.5 npm ERR! npm v3.10.10 npm ERR! code ELIFECYCLE npm ERR! functions@ lint: eslint . npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the functions@ lint script 'eslint .'. npm ERR! Make sure you have the latest version of node.js and npm installed. npm ERR! If you do, this is most likely a problem with the functions package, npm ERR! not with npm itself. npm ERR! Tell the author that this fails on your system: npm ERR! eslint . npm ERR! You can get information on how to open an issue for this project with: npm ERR! npm bugs functions npm ERR! Or if that isn't available, you can get their info via: npm ERR! npm owner ls functions npm ERR! There is likely additional logging output above. npm ERR! Please include the following file with any support request: npm ERR! C:\Users\TahirAliAwan\Desktop\Function\npm-debug.log Error: functions predeploy error: Command terminated with non-zero exit code1

are you retreiving the userid twice? Also remove the .then function you won't get an error — Peter Haddad
When showing errors on Stack Overflow, please copy the entire text of the error into the question instead of showing an image. That makes it easier to read and easier to search. — Doug Stevenson
Your error output shows two warnings from TSLint and one error about always returning a value from then(). Between all those messages, it's suggesting that you restructure the promises in your code. — Doug Stevenson
@Tahiraliawan did you remove the .then(response => { console.log('This was the notification Feature');? — Peter Haddad
@Peter Hadded i removed this line but one error remaining. ` 61:11 warning Avoid nesting promises promise/no-nesting` — Tahiraliawan

Tahiraliawan Tahiraliawan · Accepted Answer · 2018-03-08T04:54:57

After @PeterHaddad tip and my effort, I solved this problem by removing this line .then(response => { console.log('This was the notification Feature'); and update nodejs. Thanks to all.

eslint throws error

1 Answers