Alternative for __dirname in node when using the --experimental-modules flag

问题

I use the flag --experimental-modules when running my node application in order to use ES6 modules.

However when I use this flag the metavariable __dirname is not available. Is there an alternative way to get the same string that is stored in __dirname that is compatible with this mode?

回答1:

As of Node.js 10.12 there's an alternative that doesn't require creating multiple files and handles special characters in filenames across platforms:

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

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

回答2:

There have been proposals about exposing these variables through import.meta, but for now, you need a hacky workaround that I found here:

// expose.js
module.exports = {__dirname};

// use.mjs
import expose from './expose.js';
const {__dirname} = expose;

回答3:

I used:

import path from 'path';

const __dirname = path.resolve(path.dirname(decodeURI(new URL(import.meta.url).pathname)));

decodeURI was important: used spaces and other stuff within the path on my test system.

path.resolve() handles relative urls.

回答4:

For Node 10.12 +...

Assuming you are working from a module, this solution should work, and also gives you __filename support as well

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

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

The nice thing is that you are also only two lines of code away from supporting require() for CommonJS modules. For that you would add:

import { createRequireFromPath } from 'module';
const require = createRequireFromPath(__filename);

回答5:

import path from 'path';
const __dirname = path.join(path.dirname(decodeURI(new URL(import.meta.url).pathname)));

This code also works on Windows

回答6:

I made this module es-dirname that will return the current script dirname.

import dirname from 'es-dirname'

console.log(dirname())

It works both in CommonJs scripts and in ES Modules both on Windows and Linux.

Open an issue there if have an error as the script has been working so far in my projects but it might fail in some other cases. For this reason do not use it in a production environment. And this is a temporary solution as I am sure the Node.js team will release a robust way to do it in a near future.

回答7:

I use this option, since the path starts with file:// just remove that part.

const __filename = import.meta.url.slice(7);
const __dirname = import.meta.url.slice(7, import.meta.url.lastIndexOf("/"));

回答8:

As Geoff pointed out the following code returns not the module's path but working directory.

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

works with --experimental-modules

来源：https://stackoverflow.com/questions/46745014/alternative-for-dirname-in-node-when-using-the-experimental-modules-flag

标签

node.js

ecmascript-6

es6-modules