Testing is an important part of any modern piece of software. But writing tests can quickly become an exercise in frustration, with tons of repeated code, duplicate setup routines, and cumbersome assertions. ExUnit, Elixir’s testing framework, is ultimately just pure Elixir, and so we can extend it using more elixir features. Isolated setup units that can be mixed and matched, configuration via tags, and custom assertions are trivial to add to a test suite, and can save tons of developer headache