import-meta-resolve

What is import-meta-resolve?

The import-meta-resolve package provides utilities for resolving module specifiers in the same way that Node.js does for ES modules. It allows developers to programmatically resolve specifiers from the context of a specific file or URL, which can be useful for tooling that needs to understand module resolution, bundlers, and other development tools.

What are import-meta-resolve's main functionalities?

Resolving module specifiers

This feature allows you to resolve the full path of a module specifier from a specific context, typically the URL of the importing module. The code sample demonstrates how to use the resolve function to find the full path of 'some-module' as if it were being imported from the current module.

import { resolve } from 'import-meta-resolve';

(async () => {
  const resolved = await resolve('some-module', import.meta.url);
  console.log(resolved);
})();

Other packages similar to import-meta-resolve

resolve

The 'resolve' package is a popular Node.js module resolution algorithm that can be used programmatically. It is similar to import-meta-resolve but does not specifically target ES module resolution semantics. It is more general-purpose and can resolve CommonJS modules as well.

enhanced-resolve

This package is used internally by webpack to resolve module paths. It is highly configurable and can handle complex resolution scenarios, including loaders and plugin systems. While it offers more features than import-meta-resolve, it is also more complex and tailored to webpack's ecosystem.

README

import-meta-resolve

Resolve paths in node when using es modules (or commonjs). Ponyfill for import.meta.resolve as it is behind a flag.

Installation

npm i import-meta-resolve

Features

• can be used in node using es modules & commonjs
• resolves folders (require.resolve dos not support it)
• mimics import.meta.url so can hopefully be replaced by it once it is no longer behind a flag

Usage

import { importMetaResolve } from 'import-meta-resolve';

await importMetaResolve('@foo/bar/some-folder', import.meta.url);
// file:///absolute/path/node_modules/@foo/bar/some-folder

await importMetaResolve('@foo/bar', import.meta.url);
// file:///absolute/path/node_modules/@foo/bar/

await importMetaResolve('@foo/bar/some-file.js', import.meta.url);
// file:///absolute/path/node_modules/@foo/bar/some-file.js

await importMetaResolve('./foo.js', import.meta.url);
// file:///absolute/path/to/file/foo.js

Will throw if file could not be resolved

try {
  await importMetaResolve('@foo/bar/non-existing-file.js', import.meta.url);
} catch (error) {
  // Cannot find module '@foo/bar/non-existing-file.js' imported from /absolute/path/to/current/file.js
}

Usage CommonJs

const { importMetaResolve } = require('import-meta-resolve');

await importMetaResolve('@foo/bar/some-folder', __file);
// file:///absolute/path/node_modules/@foo/bar/some-folder

Motivation

require.resolve enables you to resolve package files which can be useful if you need to manually load or check for files in packages. However when using es modules in node require.resolve is not allowed. Which means there is currently no replacement for this functionality. There is however an experimental api import.meta.resolve which you can enable via a cli flag --experimental-import-meta-resolve. Experimental flags are however tough to integrate everywhere bins, other tools, ... and additionally it is tough to explain to your users that the have to do this.

Because of this a transition package like this may be useful.