Help with Ruby Koans #6 - What exception has been caught?

Question

I'm trying to learn Ruby through Koans but I'm stuck on the 6th step.

Here's the 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 => 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

I know I'm supposed to replace the __ with something to do with the error message "NoMethodError" but I can't seem to figure it out.

This is the error message that I get when I run the "path_to_enlightenment.rb":

The answers you seek...
  <"FILL ME IN"> expected but was  <NoMethodError>.

I would really appreciate some guidance with this - it's driving me insane! I would love to know the answer and a possible explanation. Thank you!

Answer 1

The answer here is "NoMethodError"

you need the items on either side of the , to be equal, therefore making them both ex.class will do that.

Then you'll need to go on to /__/ Below.

Answer 2

I had to put the assert_equal statement into parens to get this one to pass. Must be a bug.

  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 => ex
      # What exception has been caught?
      assert_equal(NoMethodError, ex.class)

      # What message was attached to the exception?
      # (HINT: replace __ with part of the error message.)
      assert_match("undefined method", ex.message)
    end
  end

Answer 3

You need to substitute __ with the actual

assert_equal NoMethodError, ex.class