Importing CommonJS modules to an ESM syntax

Question

I'm struggling to understand how to import CommonJS modules into an ESM syntax. I'm currently trying to work with the library url-metadata. url-metadata exposes a top-level export as a callable (which does not really conform to CommonJS, AFAIK):

const urlMetadata = require('url-metadata')
urlMetadata(URL, ...)

It's not possible to write:

import urlMetadata from 'urlMetadata'

since no default export is defined.

Instead, I have to write:

import * as urlMetadata from 'url-metadata'

Or:

import urlMetadata = require("url-metadata")

I tried to read up on module loading in Node but I'm still somewhat confused as to what is the correct way to do this and why.

Answer 1

import urlMetadata from 'url-metadata';

is syntactic sugar for

import { default as urlMetadata } from 'url-metadata';

Either will work fine.

The value assigned to module.exports in a CommonJS module is the default export.

See the Node.js docs.