Node.js — How to Fix ESM Error “Directory import is not supported resolving ES modules imported”

ECMAScript modules are an official standard describing a format on how to write reusable JavaScript code. Browsers used ECMAScript modules and Node.js had their own module loading implementation: CommonJS. Node.js added full ESM support starting from version 12.

At the time of writing this tutorial, developers migrate their CommonJS code to use ESM. This migration surfaces a handful of compatibility errors when changing the module type. One of the errors is the directory import. This tutorial shows you how to fix directory imports when using ECMAScript modules.

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TL;DR

ESM doesn’t support directory imports. You must import file references, with file extension:

import { something } from '../dist/index.js'   // ✅ ensure you’re importing with file extension  

Fixing the Error: Directory Import Is Not Supported

CommonJS allows directory imports by referencing a directory as a module. The module loader then looked for an index.js (or index.cjs) file within the referenced directory. This index file was used as the module and all exports from that file are available to the outside.

import { test } from 'node:test'  
import { Manager } from '../dist/index'   // 👈 this line creates the issue in ESM, but works in CJS

test('test name', () => {  
  // …
})

ESM in contrast comes with unsupported directory import. You can’t change your module type from CommonJS to ESM when using directory imports. Running your code in ESM prints the following error in the terminal:

Error [ERR_UNSUPPORTED_DIR_IMPORT]: Directory import '/Users/marcus/Projects/supercharge/framework/packages/manager/dist' is not supported resolving ES modules imported from /Users/marcus/Projects/supercharge/framework/packages/manager/test/manager.js  
    at new NodeError (node:internal/errors:406:5)
    at finalizeResolution (node:internal/modules/esm/resolve:227:11)
    at moduleResolve (node:internal/modules/esm/resolve:845:10)
    at defaultResolve (node:internal/modules/esm/resolve:1043:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:383:12)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:352:25)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:228:38)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:85:39)
    at link (node:internal/modules/esm/module_job:84:36)
npm ERR! Lifecycle script `test:run` failed with error:  

In ESM, you must use file references. Change the import from the directory ../dist import to a file import '../dist/index.js' and let the ESM loader resolve the exported variables:

import { test } from 'node:test'  
import { Manager } from '../dist/index.js'   // ✅ use a file reference, with file extension

test('test name', () => {  
  // …
})

That’s it!


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