Generate test methods depending on the number of arguments.

lib/koans.ex

@@ -1,10 +1,12 @@
 defmodule Koans do
   defmacro koan(name, body) do
     compiled_name = String.to_atom(name)
-    expanded_answers = expand(ASTMangler.count(body))
-    mangled_body = ASTMangler.expand(body, expanded_answers)
+    number_of_args = ASTMangler.count(body)
     quote do
       @koans unquote(compiled_name)
+
+      generate_test_method(unquote(compiled_name), unquote(number_of_args), unquote(body))
+
       def unquote(compiled_name)() do
         try do
           unquote(body)
@@ -13,17 +15,34 @@ defmodule Koans do
           e in _ -> e
         end
       end
+    end
+  end
 
-      def unquote(compiled_name)(answer) when is_list(answer) do
-        converted = List.to_tuple(answer)
-        unquote(mangled_body)
+  defmacro generate_test_method(_name, 0, _body), do: false
+  defmacro generate_test_method(name, 1, body) do
+    single_var = ASTMangler.expand(body, Macro.var(:answer, Koans))
+    quote do
+      def unquote(name)(answer) do
+        converted = {answer}
+        unquote(single_var)
+        :ok
+      end
+    end
+  end
+  defmacro generate_test_method(name, number_of_args, body) do
+    answer_placeholders = expand(number_of_args)
+    multi_var = ASTMangler.expand(body, answer_placeholders)
+    quote do
+      def unquote(name)({:multiple, answers}) do
+        converted = List.to_tuple(answers)
+        unquote(multi_var)
         :ok
       end
     end
   end
 
   def expand(amount) do
-    Enum.map(0..amount, fn (idx) -> {:elem, [context: Koans, import: Kernel], [{:converted, [], Koans}, idx]} end)
+    Enum.map(0..amount, fn (idx) -> quote do: elem(converted, unquote(idx)) end)
   end
 
   defmacro __using__(_opts) do