__dirname is not defined in Node 14 version

Question

I have been using Node version 12.3.4 updated it to 14.14.0 and started to receive a lot of issues which I fixed. The only thing that I don't understand is the issue

__dirname is not defined

__dirname is a core variable in Node as I know, Is it removed in Node 14?

Is this in MJS or CJS? In MJS mode you need [a shim](https://stackoverflow.com/questions/46745014/alternative-for-dirname-in-node-when-using-the-experimental-modules-flag) since it works differently with `import`. — tadman, Oct 16 '20 at 06:23
[documentation](https://nodejs.org/api/esm.html#esm_no_require_exports_module_exports_filename_dirname) — Jaromanda X, Oct 16 '20 at 06:27

score 129 · Accepted Answer · answered Oct 16 '20 at 06:28

129

How are you loading the file? According to this issue, the problem arises if you load it as an ECMAScript module which do not contain __dirname.

https://github.com/nodejs/help/issues/2907#issuecomment-671782092

Following the documentation below you may be able to resolve the issue: https://nodejs.org/api/esm.html#esm_no_require_exports_module_exports_filename_dirname

import { fileURLToPath } from 'url';
import { dirname } from 'path';

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

answered Oct 16 '20 at 06:28

adlopez15

2,229
2
11
18

Great! It works, got it. – sudhee_bsp Oct 28 '21 at 05:14
Great answer. Worked like charm. – raj240 Dec 09 '21 at 10:04
1

I was getting "dirname is not defined", so the last line I had to change to `const __dirname = path.dirname(__filename);` – 6bytes Feb 28 '22 at 22:22
This matches "official" advice on https://github.com/nodejs/help/issues/2907#issuecomment-757446568 – Beni Cherniavsky-Paskin Mar 28 '22 at 18:37

score 70 · Answer 2 · edited Jun 28 '21 at 18:59

70

My code before was like below.

app.use(express.static(path.join(__dirname, 'public')));

And I got this error.

ReferenceError: __dirname is not defined in ES module scope

And I solved this by adding code below.

import path from 'path';
const __dirname = path.resolve();

edited Jun 28 '21 at 18:59

padaleiana

687
1
14
22

answered Jun 28 '21 at 12:58

Jiyoon Hur

858
4
4

23

This only resolves the cwd of the node process, so e.g. `node myscript.mjs` will work but `node dir/myscript.mjs` will not. – Dan Sep 10 '21 at 22:13
This one solved my problem. – Nilay Singh Apr 05 '22 at 08:16

score 26 · Answer 3 · answered Jan 08 '21 at 13:12

26

There's usually no need to import from 'url' or 'path'.

E.g. (using ESM)

fs.readFileSync(new URL('myfile.txt', import.meta.url));

will read myfile.txt from the directory of the JavaScript file (not from the current working directory).

answered Jan 08 '21 at 13:12

ChrisV

8,274
3
46
38

Cool solution, but doesn't feel very clear to those not in the know and/or not working in a browser context where using URL seems a bit out of place. Perhaps you could expand on when this might be particularly appropriate? – Dan Sep 10 '21 at 22:03
1

Ok, looks like I just need to update my thinking. path.resolve() only returns cwd. Other methods are long winded. URL concept is baked into ES6 modules. It seems this is the standard approach now https://stackoverflow.com/a/66651120/4682556. Thanks for this answer! – Dan Sep 10 '21 at 22:11
1

This returns a `Buffer`, if you want a string use: `fs.readFileSync(new URL('myfile.txt', import.meta.url), 'utf-8');` – Michael Stramel Oct 06 '21 at 22:27
This is awesome, thank you! No extra requires, no hacks, future proof. – Tomáš Kafka Nov 19 '21 at 15:45

score 0 · Answer 4 · answered May 11 '22 at 00:38

0

A quick fix (depending on your project) would be to ensure that "type": "module" does not exist in your package.json file

answered May 11 '22 at 00:38

Nathanael

999
2
15
36

__dirname is not defined in Node 14 version

4 Answers4

Linked