Scala.js, a safer way to build robust front-end web applications with the Scala Programming Language.

ScalaTest is a flexible and popular testing tool in the Scala ecosystem. It can be used to test Scala, Scala.js, Scala Native, Dotty (Scala 3), and Java code.

Standard library for the Scala Programming Language Version 3

ScalaCheck is a library written in Scala and used for automated property-based testing of Scala or Java programs.

Scala.js test bridge

Cats is a library which provides abstractions for functional programming in the Scala programming language.

Scala.js test interface

This library makes some new Scala APIs (mainly collections) available to older versions of Scala.

scalac-scoverage-runtime

Core classes for Specs2, a library for writing executable software specifications in Scala

Cats Effect is a high-performance, asynchronous, composable framework for building real-world applications in a purely functional style within the Typelevel ecosystem.