ESLint - 'process' is not defined

Question

I am using ESLinter for a simple node project. Below is the only code I have in index.js:

const express = require('express');
const app = express();

app.get('/', (req, res) => {
    res.send({
        hi: 'there'
    });
});

const PORT = process.env.PORT || 5000;
app.listen(PORT);

I am using VSCode editor. It automatically runs ESLint for JS code.

In the IDE, I see below error for last but one line -

[eslint] 'process' is not defined. (no-undef)

Any Idea what's wrong?

does ESLINT have some way of informing it you are linting nodejs code? — Jaromanda X, Jun 17 '18 at 05:37
You probably haven't configured eslint correctly. https://eslint.org/docs/user-guide/configuring#specifying-environments — Felix Kling, Jun 17 '18 at 05:38
Thanks @FelixKling - It was so dumb of me not looking into .eslintrc.json file. I had accidentally selected `browser default global variables`. Your link hinted me to that. Now, the error is gone! — ArunKolhapur, Jun 17 '18 at 05:42

score 315 · Accepted Answer · edited Apr 26 '22 at 09:11

315

When I got error I had "browser": true instead of "node": true.

I have fixed this with following config for .eslintrc.json file-

{
    "env": {
        "node": true,
        "commonjs": true
    },
    "extends": "eslint:recommended",
    "rules": {
        "indent": [
            "error",
            "tab"
        ],
        "linebreak-style": [
            "error",
            "unix"
        ],
        "quotes": [
            "error",
            "single"
        ],
        "semi": [
            "error",
            "always"
        ]
    },
    "parserOptions": {
        "ecmaVersion": 2015
    }
}

Thanks @FelixKling and @Jaromanda X for quick responses.

edited Apr 26 '22 at 09:11

mikemaccana

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answered Jun 17 '18 at 05:47

ArunKolhapur

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31

This got rid of my ESlint 'URL' is not defined, too. – Mark Swardstrom Feb 07 '19 at 00:49
3

In my case I was missing the ```node: true``` on my env eslint config file. – try_catch Mar 01 '22 at 01:54
1

Adding the `"node" : true` worked for me also with this issue. – Josh Mar 18 '22 at 13:46
Thought I selected "node" in the wizard at npm init @eslint/config but seems I didn't heh – Arno Teigseth Nov 17 '22 at 18:53

score 101 · Answer 2 · answered Apr 10 '19 at 04:59

101

Adding "node": "true" to an existing list of environments will do the job, too

"env": {
        "node": true,
        "commonjs": true,
        "browser": true,
        "es6": true
       }

answered Apr 10 '19 at 04:59

crtag

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score 58 · Answer 3 · answered Jun 26 '19 at 16:09

58

Add .eslintrc file to root of your project (if you don't already have one) and define globals to ignore

{
    "globals": {
        "process": true
      }
}

Make sure you use process.env though out the project but only in a single configuration file. Consider adding no-process-envrule.

https://eslint.org/docs/rules/no-process-env

answered Jun 26 '19 at 16:09

t-reksio

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This is useful if you're using a bundler like [Parcel](https://parceljs.org/), which exposes `process` in a browser context. – Ben Grant Jul 06 '22 at 03:49
2

This is the correct way if your're implementing a frontend application. – moeabdol Sep 02 '22 at 02:27

score 35 · Answer 4 · answered Mar 28 '21 at 06:21

35

If you have eslint installed, add env: { node: true } to the .eslintrc.js file

answered Mar 28 '21 at 06:21

youngwolf

461
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4

score 11 · Answer 5 · edited Aug 17 '22 at 17:30

11

This config helped me and can help others too.

{
  "parser": "babel-eslint",
  "parserOptions": {
    "ecmaFeatures": {
      "jsx": true,
      "modules": true
    },
    "ecmaVersion": 2020,
    "sourceType": "module",
    "useJSXTextNode": true,
    "warnOnUnsupportedTypeScriptVersion": false
  },
  "root": true,
  "env": {
    "browser": true,
    "es6": true,
    "node": true,
    "commonjs": true
  },
  "extends": [ "eslint:recommended"],
  }
}

edited Aug 17 '22 at 17:30

M. Hamza Rajput

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answered Jun 22 '20 at 21:06

Paulo Andrade

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I just had to add "parser": "babel-eslint" to my .eslintrc.json file – ttemple Mar 01 '23 at 17:53

score 7 · Answer 6 · edited Aug 17 '22 at 17:29

When working on the node js project. This might help you. It is working on my end.

module.exports = {
    "env": {
        "node": true,
        "browser": true,
        "commonjs": true,
        "es6": true
    },
    "extends": "eslint:recommended",
    "globals": {
        "Atomics": "readonly",
        "SharedArrayBuffer": "readonly"
    },
    "parserOptions": {
        "ecmaVersion": 2018
    },
    "rules": {
    }
};

score 2 · Answer 7 · answered Mar 03 '22 at 18:28

2

If you are getting the error even after settng "node": true, remember to install @types/node with

npm i -D @types/node

yarn add -D @types/node

answered Mar 03 '22 at 18:28

tHeSiD

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score 0 · Answer 8 · answered Aug 17 '22 at 17:25

Add these env lines in your `.eslintrc.js` file.

module.exports = {
    "env": {
        "browser": true,
        "commonjs": true,
        "node": true,
        "es2021": true,
        "jest": true
    },
    "extends": "eslint:recommended",
    "parserOptions": {
        "ecmaVersion": "latest"
    },
    "rules": {
    }
}

score 0 · Answer 9 · answered Apr 22 '23 at 18:03

In the new ESLint configuration file eslint.config.js, the env property has been removed so you should use the languageOptions.globals property:

import globals from 'globals';

export default [
  {
    languageOptions: {
      globals: {
        ...globals.browser
      }
    }
  }
];

score -6 · Answer 10 · answered Jan 19 '21 at 20:56

-6

Another remedy for this issue is to simply import process from "process".

Even though it's not strictly necessary, one could argue it's better practice anyway.

answered Jan 19 '21 at 20:56

P Varga

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ESLint - 'process' is not defined

10 Answers10

Add these env lines in your `.eslintrc.js` file.

Linked

ESLint - 'process' is not defined

10 Answers10

Add these env lines in your .eslintrc.js file.

Linked

Add these env lines in your `.eslintrc.js` file.