Improve and enforce naming of koans at compile time

lib/koans.ex

@@ -1,5 +1,12 @@
 defmodule Koans do
+  defp valid_name(name) do
+    Regex.match?(~r/([A-Z]|\.\.\.).+/, name)
+  end
+
   defmacro koan(name, body) do
+    if not valid_name(name) do
+      raise "Name does not start with a capital ltter: #{name}"
+    end
     compiled_name = String.to_atom(name)
     number_of_args = Blanks.count(body)
     quote do

lib/koans/02_arithmetic.ex

@@ -1,52 +1,51 @@
 defmodule Arithmetic do
   use Koans
 
-  koan "it can add numbers" do
+  koan "It can add numbers" do
     assert 3 + :__ == 7
   end
 
-  koan "it can substract numbers" do
+  koan "It can substract numbers" do
     assert 7 - 4 == :__
   end
 
-  koan "it can multiply" do
+  koan "It can multiply" do
     assert 3 * 4 == :__
   end
 
-  koan "floats and integers can be equal..." do
+  koan "Floats and integers can be equal..." do
     assert 3.0 == :__
   end
 
-  koan "..unless they are not precisely the same" do
+  koan "...unless they are not precisely the same" do
     assert 3.2 != :__
   end
 
-  koan "it does floating point division" do
+  koan "It does floating point division" do
     assert 5 / 2 == :__
   end
 
-  koan "it does integer division" do
+  koan "It does integer division" do
     numerator = 5
     denominator = 2
     assert div(numerator, denominator) == :__
   end
 
-  koan "it calculates the remainder of a division" do
+  koan "It calculates the remainder of a division" do
     numerator = 5
     denominator = 2
     assert rem(numerator, denominator) == :__
   end
 
-  koan "it finds the maximum in a list" do
+  koan "It finds the maximum in a list" do
     assert Enum.max([1,2,3,4]) == :__
   end
 
-  koan "it finds the minimum in a list" do
+  koan "It finds the minimum in a list" do
     assert Enum.min([1,2,3,4]) == :__
   end
 
-  koan "it can compare numbers" do
+  koan "It can compare numbers" do
     assert 5 > :__
   end
-
 end

lib/koans/10_enums.ex

@@ -16,7 +16,7 @@ defmodule Enums do
   end
 
   def even?(n), do: rem(n, 2) == 0
-  koan "sometimes you you just want to know if there are any elements fullfilling a condition" do
+  koan "Sometimes you you just want to know if there are any elements fullfilling a condition" do
     assert Enum.any?([1,2,3], &even?/1) == :__
     assert Enum.any?([1,3,5], &even?/1) == :__
   end
@@ -28,7 +28,7 @@ defmodule Enums do
   end
 
   def multiply_by_ten(n), do: 10 * n
-  koan "map converts each element of a list by running some function with it" do
+  koan "Map converts each element of a list by running some function with it" do
     assert Enum.map([1,2,3], &multiply_by_ten/1) == :__
   end
 

lib/koans/12_task.ex

@@ -28,7 +28,7 @@ defmodule Tasks do
     assert Task.shutdown(handle) == :__
   end
 
-  koan "shutdown will give you an answer if it has it" do
+  koan "Shutdown will give you an answer if it has it" do
     handle = Task.async(fn -> 3 * 3 end)
     :timer.sleep(10)
     assert Task.shutdown(handle) == {:ok, :__}

test/support/passing_koan.ex

@@ -1,7 +1,7 @@
 defmodule PassingKoan do
   use Koans
 
-  koan "hi there" do
+  koan "Hi there" do
     assert 1 == 1
   end
 end

test/support/sample_koan.ex

@@ -1,7 +1,7 @@
 defmodule SampleKoan do
   use Koans
 
-  koan "thinking more than once" do
+  koan "Thinking more than once" do
     assert 3 == :__
     assert 4 == :__
   end