Because jest is using barrel files it's very slow, and each test consumes ALL the imported code. Using esbuild I'm bundling all the tests and the code into one big file, and give that to jest. Making the tests run X10 faster.
Sample repository that would demonstrate how to use jest with ESM module
🐠 🃏 🚀 - Brings tree-shaking to Jest, speeding up your test runs, using Babel
🏍 A fast JavaScript test framework
🔴🟡 🟢 Zero Configuration JavaScript Bundler
JavaScript Mocking Fundamentals on TestingJavaScript.com
vue-test-utils-set-props-issue
eslint plugin to avoid common errors with barrel files
build everything on esbuild
A teeny-tiny alternative to bundlers that does just what you need (and nothing more), using `esbu...
A demo repository for building only as needed with WebpackDevServer.
A flexible ESNext modern JavaScript engine running on another JavaScript engine.
An extremely fast bundler for the web