Extract display for formatting purposes

lib/display.ex

@@ -0,0 +1,40 @@
+defmodule Display do
+  alias IO.ANSI
+
+  def show_failure(%{expr: expr}, module, name) do
+    source = module.__info__(:compile)
+              |> Dict.get(:source)
+              |> Path.relative_to(File.cwd!)
+    IO.puts("")
+    IO.puts("Now meditate upon #{display_module(module)}")
+    IO.puts("---------------------------------------")
+    IO.puts("Assertion failed in #{source}:#{line_number(expr)}")
+    IO.puts(display_koan(name))
+    IO.puts(format_red(Macro.to_string(expr)))
+  end
+
+  def considering(module) do
+    IO.puts("Considering #{display_module(module)}...")
+  end
+
+  def before_run do
+    IO.puts("")
+    IO.puts("")
+  end
+
+  defp line_number({_, [line: line], _}) do
+    line
+  end
+
+  defp format_red(str) do
+    Enum.join([ANSI.red, str, ANSI.reset], "")
+  end
+
+  defp display_module(module) do
+    Module.split(module) |> List.last
+  end
+
+  defp display_koan(name) do
+    String.replace(to_string(name), "koan: ", "")
+  end
+end

lib/runner.ex

@@ -1,6 +1,4 @@
 defmodule Runner do
-  alias IO.ANSI
-
   @modules [
     Equalities,
     Lists
@@ -11,31 +9,24 @@ defmodule Runner do
   end
 
   def run(start_module) do
-    IO.puts("")
+    Display.before_run
-    IO.puts("")
 
     start_idx = Enum.find_index(@modules, &(&1 == start_module))
     Enum.drop(@modules, start_idx)
     |> Enum.take_while(fn(mod) ->
       run_module(mod) == :passed
     end)
-
-    IO.puts("")
   end
 
   def run_module(module) do
-    IO.puts("Considering #{display_module(module)}...")
+    Display.considering(module)
 
-    functions = module.__info__(:functions)
+    koans = extract_koans_from(module)
-
-    koans = Enum.map(functions, fn({name, _arity}) -> name end)
-    |> Enum.filter(&koan?/1)
 
     passed = Enum.take_while(koans, fn(name) ->
       run_koan(module, name) == :passed
     end)
 
-
     if Enum.count(koans) == Enum.count(passed) do
       :passed
     else
@@ -47,40 +38,18 @@ defmodule Runner do
     case apply(module, name, []) do
       :ok   -> :passed
       error ->
-        show_failure(error, module, name)
+        Display.show_failure(error, module, name)
         :failed
     end
   end
 
-  def show_failure(%{expr: expr}, module, name) do
+  defp extract_koans_from(module) do
-    source = module.__info__(:compile)
+    module.__info__(:functions)
-              |> Dict.get(:source)
+    |> Enum.map(fn({name, _arity}) -> name end)
-              |> Path.relative_to(File.cwd!)
+    |> Enum.filter(&koan?/1)
-    IO.puts("")
-    IO.puts("Now meditate upon #{display_module(module)}")
-    IO.puts("---------------------------------------")
-    IO.puts("Assertion failed in #{source}:#{line_number(expr)}")
-    IO.puts(display_koan(name))
-    IO.puts(format_red(Macro.to_string(expr)))
-  end
-
-  def line_number({_, [line: line], _}) do
-    line
-  end
-
-  def format_red(str) do
-    Enum.join([ANSI.red, str, ANSI.reset], "")
   end
 
   defp koan?(fun_name) do
     String.starts_with?(to_string(fun_name), "koan: ")
   end
-
-  defp display_module(module) do
-    Module.split(module) |> List.last
-  end
-
-  defp display_koan(name) do
-    String.replace(to_string(name), "koan: ", "")
-  end
 end