This is a JavaScript library for writing composable, strongly typed, and curried test assertions that work with any test framework supporting assertions that throw errors, like Mocha. It provides a set of assertion functions (eq, is, assert, throws, rejects, where, fail) that enable concise, readable test code with support for partial application and composition. The library is designed for developers writing unit tests who want type-safe, functional-style assertions that can be easily combined and reused.