Which package?

@formatjs/fast-memoize

Describe the bug

The main property of @formatjs/fast-memoize is a CommonJS module that specifies module.exports.default. There is no (real) ESM support. That means that usage in CommonJS is as follows:

const memoize = require('@formatjs/fast-memoize')

memoize.default(/* … */)

and usage in ESM is:

import memoize from '@formatjs/fast-memoize'

memoize.default(/* … */)

IMO this is not pretty, but it works.

The problem is that @formatjs/fast-memoize does specify the module field. This points to a faux ESM module. Many bundlers use this field, so correct use with a bundler is:

import memoize from '@formatjs/fast-memoize'

memoize(/* … */)

This means it’s not possible to use @formatjs/fast-memoize in isomorphic code.

To Reproduce

Codesandbox URL

N/A

Reproducible Steps/Repo

1. Create the following script named test.mjs:

   import memoize from '@formatjs/fast-memoize';
   
   console.log(memoize);
   ``

2. Run the following script using Node.js:

   node test.mjs

Notice that memoize is a module with the property default. memoize itself is not a function.

Expected behavior

I would expect at least one of the following:

1. @formatjs/fast-memoize supports proper dual packaging using package exports.
2. @formatjs/fast-memoize removes support for CommonJS.
3. @formatjs/fast-memoize removes support for faux ESM.
4. @formatjs/fast-memoize uses a named export instead of a default export.
5. @formatjs/fast-memoize gets deprecated in favour of fast-memoize.

A clear and concise description of what you expected to happen.

Screenshots

N/A

Desktop (please complete the following information):

• OS: Pop!_OS
• Browser: Node.js
• Version: 18

Smartphone (please complete the following information):

• Device: N/A
• OS: N/A
• Browser N/A
• Version N/A

Additional context

@formatjs/fast-memoize was created because of a very niche issue (#1913). fast-memoize uses CommonJS (not UMD, as is claimed in that issue). Node.js native ESM and bundlers can consume CJS just fine. A lot of ESM packages have CJS dependencies.