39 lines
1.0 KiB
Ruby
39 lines
1.0 KiB
Ruby
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require File.expand_path(File.dirname(__FILE__) + '/edgecase')
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class AboutNil < EdgeCase::Koan
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def test_nil_is_an_object
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assert_equal __, nil.is_a?(Object), "Unlike NULL in other languages"
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end
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def test_you_dont_get_null_pointer_errors_when_calling_methods_on_nil
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# What happens when you call a method that doesn't exist. The
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# following begin/rescue/end code block captures the exception and
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# make some assertions about it.
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begin
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nil.some_method_nil_doesnt_know_about
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rescue Exception => ex
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# What exception has been caught?
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assert_equal __, ex.class
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# What message was attached to the exception?
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# (HINT: replace __ with part of the error message.)
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assert_match(/__/, ex.message)
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end
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end
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def test_nil_has_a_few_methods_defined_on_it
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assert_equal __, nil.nil?
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assert_equal __, nil.to_s
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assert_equal __, nil.inspect
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# THINK ABOUT IT:
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#
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# Is it better to use
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# obj.nil?
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# or
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# obj == nil
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# Why?
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end
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end
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