69 lines
1.6 KiB
Ruby
69 lines
1.6 KiB
Ruby
require File.expand_path(File.dirname(__FILE__) + '/neo')
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class AboutExceptions < Neo::Koan
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class MySpecialError < RuntimeError
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end
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def test_exceptions_inherit_from_Exception
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assert_equal __, MySpecialError.ancestors[1]
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assert_equal __, MySpecialError.ancestors[2]
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assert_equal __, MySpecialError.ancestors[3]
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assert_equal __, MySpecialError.ancestors[4]
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end
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def test_rescue_clause
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result = nil
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begin
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fail "Oops"
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rescue StandardError => ex
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result = :exception_handled
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end
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assert_equal __, result
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assert_equal __, ex.is_a?(StandardError), "Should be a Standard Error"
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assert_equal __, ex.is_a?(RuntimeError), "Should be a Runtime Error"
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assert RuntimeError.ancestors.include?(StandardError),
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"RuntimeError is a subclass of StandardError"
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assert_equal __, ex.message
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end
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def test_raising_a_particular_error
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result = nil
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begin
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# 'raise' and 'fail' are synonyms
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raise MySpecialError, "My Message"
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rescue MySpecialError => ex
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result = :exception_handled
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end
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assert_equal __, result
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assert_equal __, ex.message
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end
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def test_ensure_clause
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result = nil
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begin
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fail "Oops"
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rescue StandardError
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# no code here
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ensure
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result = :always_run
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end
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assert_equal __, result
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end
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# Sometimes, we must know about the unknown
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def test_asserting_an_error_is_raised
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# A do-end is a block, a topic to explore more later
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assert_raise(___) do
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raise MySpecialError.new("New instances can be raised directly.")
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end
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end
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end
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