Firebase Cloud Function - Parsing error: Unexpected token => - node.js

Question

I have a problem during deploy the functions into Cloud Function. I do believe before I put the const admin = require('firebase-admin') and admin.initializeApp() there will be a problem after I place these two, but before I place the two-line there is no problem occurred.
This is my full code for index.js
const functions = require("firebase-functions");
const express = require('express');
const cors = require('cors');
const admin = require('firebase-admin');
admin.initializeApp();
const app = express();
app.get('/', (req, res) => {
});
app.post("/", async (req, res) => {
const user = req.body;
await admin.firestore().collection("users").add(user);
res.status(201).send();
});
exports.user = functions.https.onRequest(app)
package.json
{
"name": "functions",
"description": "Cloud Functions for Firebase",
"scripts": {
"lint": "eslint .",
"serve": "firebase emulators:start --only functions",
"shell": "firebase functions:shell",
"start": "npm run shell",
"deploy": "firebase deploy --only functions",
"logs": "firebase functions:log"
},
"engines": {
"node": "12"
},
"main": "index.js",
"dependencies": {
"firebase-admin": "^9.2.0",
"firebase-functions": "^3.11.0"
},
"devDependencies": {
"eslint": "^7.6.0",
"eslint-config-google": "^0.14.0",
"firebase-functions-test": "^0.2.0"
},
"private": true
}
.eslintrc.js
module.exports = {
root: true,
env: {
es6: true,
node: true,
},
extends: [
"eslint:recommended",
"google",
],
rules: {
quotes: ["error", "double"],
},
};

Answer 1

Try adding the second part to your package.json:
{
"parserOptions": {
"ecmaVersion": 2017
}
}

Answer 2

"parser": "babel-eslint" - add this to your.eslintrc.js and run npm install babel-eslint --save this will resolve the issue.