NPM start error with webpack - node.js

Question

I am learning Javascript ES6. So I have installed NodeJS along with webpack. When I run the command npm start I get the following error:
C:\Users\Saipriyank\es6>npm start
> es6#1.0.0 start C:\Users\Saipriyank\es6
> webpack --mode development
C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\cli.js:244
throw err;
^
ReferenceError: pat is not defined
at Object.<anonymous> (C:\Users\Saipriyank\es6\webpack.config.js:6:9)
at Module._compile (C:\Users\Saipriyank\es6\node_modules\v8-compile-cache\v8-compile-cache.js:178:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)
at Module.require (module.js:596:17)
at require (C:\Users\Saipriyank\es6\node_modules\v8-compile-cache\v8-compile-cache.js:159:20)
at WEBPACK_OPTIONS (C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\convert-argv.js:133:13)
at requireConfig (C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\convert-argv.js:135:6)
at C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\convert-argv.js:142:17
at Array.forEach (<anonymous>)
at module.exports (C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\convert-argv.js:140:15)
at yargs.parse (C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\cli.js:241:39)
at Object.parse (C:\Users\Saipriyank\es6\node_modules\yargs\yargs.js:552:18)
at C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\cli.js:219:8
at Object.<anonymous> (C:\Users\Saipriyank\es6\node_modules\webpack-cli\bin\cli.js:530:3)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)
at Module.require (module.js:596:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (C:\Users\Saipriyank\es6\node_modules\webpack\bin\webpack.js:157:2)
at Module._compile (module.js:652:30)
at Object.Module._extensions..js (module.js:663:10)
at Module.load (module.js:565:32)
at tryModuleLoad (module.js:505:12)
at Function.Module._load (module.js:497:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! es6#1.0.0 start: `webpack --mode development`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the es6#1.0.0 start 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\Saipriyank\AppData\Roaming\npm-cache\_logs\2018-08-29T05_47_41_511Z-debug.log
Here is the generated log file:
0 info it worked if it ends with ok
1 verbose cli [ 'C:\\Program Files\\nodejs\\node.exe',
1 verbose cli 'C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js',
1 verbose cli 'start' ]
2 info using npm#5.6.0
3 info using node#v8.11.3
4 verbose run-script [ 'prestart', 'start', 'poststart' ]
5 info lifecycle es6#1.0.0~prestart: es6#1.0.0
6 info lifecycle es6#1.0.0~start: es6#1.0.0
7 verbose lifecycle es6#1.0.0~start: unsafe-perm in lifecycle true
8 verbose lifecycle es6#1.0.0~start: PATH: C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\node-gyp-bin;C:\Users\Saipriyank\es6\node_modules\.bin;C:\Ruby24-x64\bin;System\;C:\Python27\;C:\Python27\Scripts;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\ATI Technologies\ATI.ACE\Core-Static;C:\xampp\php;C:\composer;C:\Program Files\Git\cmd;C:\Program Files\nodejs\;C:\Users\Saipriyank\AppData\Local\Microsoft\WindowsApps;C:\Users\Saipriyank\AppData\Roaming\npm
9 verbose lifecycle es6#1.0.0~start: CWD: C:\Users\Saipriyank\es6
10 silly lifecycle es6#1.0.0~start: Args: [ '/d /s /c', 'webpack --mode development' ]
11 silly lifecycle es6#1.0.0~start: Returned: code: 1 signal: null
12 info lifecycle es6#1.0.0~start: Failed to exec start script
13 verbose stack Error: es6#1.0.0 start: `webpack --mode development`
13 verbose stack Exit status 1
13 verbose stack at EventEmitter.<anonymous> (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\index.js:285:16)
13 verbose stack at emitTwo (events.js:126:13)
13 verbose stack at EventEmitter.emit (events.js:214:7)
13 verbose stack at ChildProcess.<anonymous> (C:\Program Files\nodejs\node_modules\npm\node_modules\npm-lifecycle\lib\spawn.js:55:14)
13 verbose stack at emitTwo (events.js:126:13)
13 verbose stack at ChildProcess.emit (events.js:214:7)
13 verbose stack at maybeClose (internal/child_process.js:925:16)
13 verbose stack at Process.ChildProcess._handle.onexit (internal/child_process.js:209:5)
14 verbose pkgid es6#1.0.0
15 verbose cwd C:\Users\Saipriyank\es6
16 verbose Windows_NT 10.0.16299
17 verbose argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "start"
18 verbose node v8.11.3
19 verbose npm v5.6.0
20 error code ELIFECYCLE
21 error errno 1
22 error es6#1.0.0 start: `webpack --mode development`
22 error Exit status 1
23 error Failed at the es6#1.0.0 start script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 1, true ]
The same problem also comes when I hit the npm run start command.
I am very new to nodeJS so I really need to figure out how things work around.
Any help would be appreciated.
Thanks in advance.
Here is package.json file:
{
"name": "es6",
"version": "1.0.0",
"main": "index.js",
"scripts": {
"start": "webpack --mode development",
"build": "webpack --mode production"
},
"keywords": [],
"author": "",
"license": "ISC",
"devDependencies": {
"webpack": "^4.12.0",
"webpack-cli": "^3.0.3"
},
"dependencies": {
"debug": "^3.1.0"
},
"description": ""
}
Here is webpack.config.js file:
const path = require('path');
module.exports = {
entry: path.resolve(__dirname, 'app'),
output: {
path: pat.resolve(__dirname, 'build'),
filename: 'bundle.js'
}
};

Answer 1

There is an error which says that pat is undefined. You must use path instead.
Please check the following code.
const path = require('path');
module.exports = {
entry: path.resolve(__dirname, 'app'),
output: {
path: path.resolve(__dirname, 'build'), // there was the problem
filename: 'bundle.js'
}
};

Answer 2

As error shows "unexpected string",
You forgot to add : between filename and bundle.js.
{
context: __dirname + "/app",
entry: "./entry",
output: {
path: __dirname + "/dist",
filename: "bundle.js"
}
}
========== EDIT ===========
As per your new update, you have spelling mistake of "pat". It should be "path".
here in this line:
path: pat.resolve(__dirname, 'build'),
this should be:
path: path.resolve(__dirname, 'build'),