eslint complains about __dirname not being defined in a NodeJS file

Question

I've just started using eslint. I initialized it and started fixing problems it pointed out. One problem, however, it shouldn't complain about:

const data = fs.readFileSync(path.join(__dirname, _FILENAME));

The error is:

error  '__dirname' is not defined

I did some searching and found that when you add --experimental to the node command that __dirname is not defined. This, however, isn't the case for me. I'm not running node with the --experimental flag.

See these questions:

Also you may check out https://stackoverflow.com/a/62892482/13163131 — humble_barnacle, Feb 01 '22 at 02:30
Does this answer your question? [Why is \_\_dirname not defined in node REPL?](https://stackoverflow.com/questions/8817423/why-is-dirname-not-defined-in-node-repl) — humble_barnacle, Feb 01 '22 at 02:31
Won't `process.cwd()` give the current working directory of the process? Sometimes you want the path of the (possibly included or required) file instead. — joecullin, Mar 23 '22 at 13:13

score 34 · Accepted Answer · answered Feb 01 '22 at 07:18

34

This is happening because ESLint does not know that your code is supposed to be used in Node.js: __dirname is not defined in browsers and also not defined in ES modules. To tell ESLint that your code will run in Node.js as a CommonJS module, open your ESLint config and set node: true in the env section. If you are using .eslintrc.json:

{
    "env": {
        "node": true
    }
}

There are also other ways to specify environments, they are explained in the related documentation.

answered Feb 01 '22 at 07:18

GOTO 0

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4

That is (to me) strange because when I ran `npm init @eslint/config`, I selected **NodeJS** as the runtime environment. I'm not sure why **browser** was selected. When I deleted `browser: true` and put in `node: true`, the problem went away. Thank you. – PatS Feb 01 '22 at 14:01
Apparently when using `npm init @eslint/config` we need to choose between browser or node by pressing the letter `i` to change the option instead of navigating with arrows. – abhiramd Jun 28 '23 at 07:06

score 6 · Answer 2 · answered Mar 23 '22 at 13:12

6

I ran into the same. Adding this to .eslintrc.json fixed it for me:

"globals": {
    "__dirname": true
}

Got the idea from this similar question about the process global: https://stackoverflow.com/a/56777068/936907

answered Mar 23 '22 at 13:12

joecullin

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I think this one is more reasonable since some projects have default global variables and this is the way to tell the Eslint which should be allowed. Thanks – Nguyễn Anh Tuấn Dec 26 '22 at 04:02

eslint complains about __dirname not being defined in a NodeJS file

2 Answers2