Extracts modules for different sections of the UI

test/display/failure_test.exs

@@ -0,0 +1,24 @@
+defmodule FailureTests do
+  use ExUnit.Case
+  alias Display.Failure
+
+  test "assertion failure with proper expression" do
+    error = error(%ExUnit.AssertionError{expr: "hi"})
+
+   assert Failure.format_failure(error) == "\e[36mAssertion failed in some_file.ex:42\e[0m\n\e[31m\"hi\"\e[0m\n"
+  end
+
+  test "assertion failure with message" do
+    error = error(%ExUnit.AssertionError{expr: :ex_unit_no_meaningful_value, message: "hola"})
+
+   assert Failure.format_failure(error) == "\e[36mAssertion failed in some_file.ex:42\e[0m\n\e[31mhola\e[0m\n"
+  end
+
+  defp error(error) do
+    %{
+      error: error,
+      file: "some_file.ex",
+      line:  42
+    }
+  end
+end