title: Ruby Koan: test_nil_is_an_object
body: <p>I have recently tried sharpening my rails skills with this tool:</p>
  
  <p><a href="http://github.com/edgecase/ruby_koans" rel="nofollow noreferrer">http://github.com/edgecase/ruby_koans</a></p>
  
  <p>but I am having trouble passing some tests. Also I am not sure if I'm doing some things correctly since the objective is just to pass the test, there are a lot of ways in passing it and I may be doing something that isn't up to standards.</p>
  
  <p>Is there a way to confirm if I'm doing things right?</p>
  
  <p>a specific example:</p>
  
  <p>in about_nil,</p>
  
  <pre><code> def test_nil_is_an_object
     assert_equal __, nil.is_a?(Object), "Unlike NULL in other languages"
   end
  </code></pre>
  
  <p>so is it telling me to check if that second clause is equal to an object(so i can say nil is an object) or just put <code>assert_equal true, nil.is_a?(Object)</code> because the statement is true?</p>
  
  <p>and the next test:</p>
  
  <pre><code>def test_you_dont_get_null_pointer_errors_when_calling_methods_on_nil
    # 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 =&gt; 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
  end
  </code></pre>
  
  <p>Im guessing I should put a "No method error" string in the assert_match, but what about the assert_equal?</p>