Merged src directory with existing koans.

koans/about_nil.rb

@@ -2,34 +2,23 @@ require 'edgecase'
 
 class AboutNil < EdgeCase::Koan
   def test_nil_is_an_object
-    #  
-    #  Hint:  '!'s negate the response from what follows.
-    #
-    assert !nil.is_a?(Object), "Unlike NULL in other languages"
+    assert_equal __, nil.is_a?(Object), "Unlike NULL in other languages"
   end
 
   def test_you_dont_get_null_pointer_errors_when_calling_methods_on_nil
-    #
-    #  What is the Exception that is thrown when you call a method that
-    #  does not exist?  
-    #
-    #  Hint:  launch irb and try the code in the block below.  
-    # 
-    #  Don't be confused by the code below yet.  It's using blocks 
-    #  which are explained later on in about_blocks.rb.  For now,
-    #  think about it like running nil.some_method_nil_doesnt_know_about
-    #  in a sandbox and catching the error class into the exception
-    #  variable.  
-    #
-    exception = assert_raise(___) do
+    # What happens when you call a method that doesn't exist.  The
+    # following begin/rescue/end code block captures the exception and
+    # make some assertions about it.
+    begin
       nil.some_method_nil_doesnt_know_about
+    rescue Exception => ex
+      # What exception has been caught?
+      assert_equal __, ex.class
+
+      # What message was attached to the exception?
+      # (HINT: replace __ with part of the error message.)
+      assert_match(/__/, ex.message)
     end
-    
-    # 
-    #  What is the error message itself? What substring or pattern could 
-    #  you test against in order to have a good idea what the string is?
-    #  
-    assert_match /__/, exception.message
   end
 
   def test_nil_has_a_few_methods_defined_on_it