In the Ruby world, a “test-unit” was the first testing library with simple DSL and set of “assertions”. As our applications became larger and more complex, we needed more powerful test frameworks. The concepts of testings also changed. Behaviour Driven Development approach shifted the testing focus from structure to behaviour. These new testing requirements brought RSpec into the Ruby world. The same happened to many other programming languages. Even though Elixir is a very young programming language, now is really the time for powerful BDD testing frameworks.