Extracts modules for different sections of the UI

lib/display/failure.ex

@@ -0,0 +1,35 @@
+defmodule Display.Failure do
+  @no_value :ex_unit_no_meaningful_value
+
+  def format_failure(%{error: %ExUnit.AssertionError{expr: @no_value, message: message}, file: file, line: line}) do
+    """
+    #{Colours.cyan("Assertion failed in #{file}:#{line}")}
+    #{Colours.red(message)}
+    """
+  end
+  def format_failure(%{error: %ExUnit.AssertionError{expr: expr}, file: file, line: line}) do
+    format_assertion_error(expr, file, line)
+  end
+  def format_failure(%{error: error, file: file, line: line}) do
+    """
+    #{Colours.cyan("Error in #{file}:#{line}")}
+    #{format_error(error)}
+    """
+  end
+
+  defp format_assertion_error(error, file, line) do
+    """
+    #{Colours.cyan("Assertion failed in #{file}:#{line}")}
+    #{Colours.red(Macro.to_string(error))}
+    """
+  end
+
+  defp format_error(error) do
+    trace = System.stacktrace |> Enum.take(2)
+    Colours.red(Exception.format(:error, error, trace))
+  end
+
+  def show_compile_error(error) do
+    format_error(error)
+  end
+end

lib/display/intro.ex

@@ -0,0 +1,15 @@
+defmodule Display.Intro do
+  def intro(module, modules) do
+    if not module in modules do
+      show_intro(module.intro)
+    else
+      ""
+    end
+  end
+
+  def show_intro(""), do: nil
+  def show_intro(message) do
+    message <> "\n"
+    |> Colours.green
+  end
+end

lib/display/notification.ex

@@ -0,0 +1,21 @@
+defmodule Display.Notifications do
+  def congratulate do
+    Colours.green("\nYou have learned much. You must find your own path now.")
+  end
+
+  def invalid_koan(koan, modules) do
+    koans_names = module_names(modules)
+    "Did not find koan #{name(koan)} in " <> koans_names
+  end
+
+  defp module_names(modules) do
+    modules
+    |> Enum.map(&Atom.to_string/1)
+    |> Enum.map(&name/1)
+    |> Enum.join(", ")
+    |> Colours.red
+  end
+
+  defp name("Elixir." <> module), do: module
+  defp name(module), do: name(Atom.to_string(module))
+end

lib/display/progress_bar.ex

@@ -0,0 +1,18 @@
+defmodule Display.ProgressBar do
+  @progress_bar_length 30
+
+  def progress_bar(%{current: current, total: total}) do
+    arrow = caluculate_progress(current, total) |> build_arrow
+
+    "|" <> String.ljust(arrow, @progress_bar_length) <> "| #{current} of #{total}"
+  end
+
+  defp caluculate_progress(current, total) do
+    round( (current/total) * @progress_bar_length)
+  end
+
+  defp build_arrow(0), do: ""
+  defp build_arrow(length) do
+    String.duplicate("=", length-1) <> ">"
+  end
+end

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

test/display/intro_test.exs

@@ -0,0 +1,13 @@
+defmodule IntroTest do
+  use ExUnit.Case
+
+  alias Display.Intro
+
+  test "module not visited yet" do
+    assert Intro.intro(SampleKoan, []) == "\e[32mThere is something\n\n\e[0m"
+  end
+
+  test "module has been visited" do
+    assert Intro.intro(SampleKoan, [SampleKoan]) == ""
+  end
+end

test/display/notification_test.exs

@@ -0,0 +1,9 @@
+defmodule NotificationTest do
+  use ExUnit.Case
+  alias Display.Notifications
+
+  test "shows possible koans when a koan can not be found" do
+    message  = Notifications.invalid_koan(SampleKoan, [PassingKoan])
+    assert message == "Did not find koan SampleKoan in \e[31mPassingKoan\e[0m"
+  end
+end

test/display/progress_bar_test.exs

@@ -1,19 +1,21 @@
-defmodule DisplayTest do
+defmodule ProgressBarTest do
   use ExUnit.Case
 
+  alias Display.ProgressBar
+
   test "empty bar" do
-    bar = Display.progress_bar(%{total: 12, current: 0})
+    bar = ProgressBar.progress_bar(%{total: 12, current: 0})
     assert bar == "|                              | 0 of 12"
   end
 
   test "puts counter on the right until half the koans are complete" do
-    bar = Display.progress_bar(%{total: 12, current: 3})
+    bar = ProgressBar.progress_bar(%{total: 12, current: 3})
     assert bar == "|=======>                      | 3 of 12"
   end
 
 
   test "full bar" do
-    bar = Display.progress_bar(%{total: 12, current: 12})
+    bar = ProgressBar.progress_bar(%{total: 12, current: 12})
     assert bar == "|=============================>| 12 of 12"
   end
 end