Merge pull request #39 from ukutaht/force_order

Force koan order using macros and attributes

lib/display.ex

@@ -8,7 +8,7 @@ defmodule Display do
     IO.puts("Now meditate upon #{display_module(module)}")
     IO.puts("---------------------------------------")
     IO.puts(format_cyan(last_failure_location))
-    IO.puts(display_koan(name))
+    IO.puts(name)
     IO.puts(format_red(Macro.to_string(expr)))
   end
 
@@ -55,8 +55,4 @@ defmodule Display do
   defp display_module(module) do
     Module.split(module) |> List.last
   end
-
-  defp display_koan(name) do
-    String.replace(to_string(name), Koans.prefix, "")
-  end
 end

lib/koans.ex

@@ -1,9 +1,8 @@
 defmodule Koans do
-  @prefix "koan: "
-
   defmacro koan(name, body) do
-    compiled_name = :"#{prefix}#{name}"
+    compiled_name = String.to_atom(name)
     quote do
+      @koans unquote(compiled_name)
       def unquote(compiled_name)() do
         try do
           unquote(body)
@@ -17,13 +16,21 @@ defmodule Koans do
 
   defmacro __using__(opts) do
     quote do
+      Module.register_attribute(__MODULE__, :koans, accumulate: true)
       require ExUnit.Assertions
       import Koans
       import BlankAssertions
+
+      @before_compile Koans
     end
   end
 
-  def prefix do
-    @prefix
+  defmacro __before_compile__(env) do
+    koans = Module.get_attribute(env.module, :koans) |> Enum.reverse
+    quote do
+      def all_koans do
+        unquote(koans)
+      end
+    end
   end
 end

lib/runner.ex

@@ -28,8 +28,7 @@ defmodule Runner do
   def run_module(module) do
     Display.considering(module)
 
-    koans = extract_koans_from(module)
-
+    koans = module.all_koans
     passed = Enum.take_while(koans, fn(name) ->
       run_koan(module, name) == :passed
     end)
@@ -49,14 +48,4 @@ defmodule Runner do
         :failed
     end
   end
-
-  defp extract_koans_from(module) do
-    module.__info__(:functions)
-    |> Enum.map(fn({name, _arity}) -> name end)
-    |> Enum.filter(&koan?/1)
-  end
-
-  defp koan?(fun_name) do
-    String.starts_with?(to_string(fun_name), Koans.prefix)
-  end
 end