== Compilation error in file lib/bucket.ex == ** (RuntimeError) cannot use ExUnit.Case without starting the ExUnit application, please call ExUnit.start() or explicitly start the :ex_unit app ну или вот
use ExUnit.Case is responsible for setting up our module for testing and imports many test-related functionality, such as the test/2 macro.
Our first test starts a new KV.Bucket by calling the start_link/1 and passing an empty list of options. Then we perform some get/2 and put/3 operations on it, asserting the result.