Feature: Support native ESM

[rschristian]

• preact-testing-library version: 2.0.1
• preact version: 10.5.13
• node version: 14.16.0
• npm (or yarn) version: yarn 1.22.10

Relevant code or config

import { render, screen } from '@testing-library/preact';

What you did:

Tried to import from @testing-library/preact'

What happened:

SyntaxError: The requested module '@testing-library/preact' does not provide an export named 'render'

      at jasmine2 (node_modules/jest-jasmine2/build/index.js:228:5)

Problem description:

Currently @testing-library/preact does not offer ESM output, which makes it unsuitable for testing in a native ESM environment. This will begin to be a problem especially now that Node 10 is EOL ("type": "module" was first valid in v12.0.0, the now oldest support version of Node).

@testing-library/react does however support ESM, so preact here is behind. Edit: Apparently not. Apparently Jest doesn't even follow the widely used practice of the module key: jestjs/jest#2702 (comment)

Suggested solution:

Offer ESM output. Will just take an alteration of the build script.

[github-actions]

🎉 This issue has been resolved in version 3.1.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[connorjclark]

Thanks @JoviDeCroock !

FYI I couldn't get an import to work until I put {"type": "module"} package.json in dist/esm.

[JoviDeCroock]

@connorjclark fixed in #58