97 lines
2.3 KiB
Ruby
97 lines
2.3 KiB
Ruby
require File.expand_path(File.dirname(__FILE__) + '/edgecase')
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class AboutBlocks < EdgeCase::Koan
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def method_with_block
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result = yield
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result
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end
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def test_methods_can_take_blocks
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yielded_result = method_with_block { 1 + 2 }
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assert_equal __, yielded_result
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end
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def test_blocks_can_be_defined_with_do_end_too
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yielded_result = method_with_block do 1 + 2 end
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assert_equal __, yielded_result
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end
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# ------------------------------------------------------------------
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def method_with_block_arguments
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yield("Jim")
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end
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def test_blocks_can_take_arguments
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result = method_with_block_arguments do |argument|
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assert_equal __, argument
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end
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end
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# ------------------------------------------------------------------
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def many_yields
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yield(:peanut)
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yield(:butter)
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yield(:and)
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yield(:jelly)
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end
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def test_methods_can_call_yield_many_times
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result = []
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many_yields { |item| result << item }
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assert_equal __, result
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end
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# ------------------------------------------------------------------
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def yield_tester
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if block_given?
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yield
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else
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:no_block
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end
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end
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def test_methods_can_see_if_they_have_been_called_with_a_block
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assert_equal __, yield_tester { :with_block }
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assert_equal __, yield_tester
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end
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# ------------------------------------------------------------------
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def test_block_can_affect_variables_in_the_code_where_they_are_created
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value = :initial_value
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method_with_block { value = :modified_in_a_block }
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assert_equal __, value
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end
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def test_blocks_can_be_assigned_to_variables_and_called_explicitly
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add_one = lambda { |n| n + 1 }
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assert_equal __, add_one.call(10)
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# Alternative calling sequence
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assert_equal __, add_one[10]
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end
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def test_stand_alone_blocks_can_be_passed_to_methods_expecting_blocks
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make_upper = lambda { |n| n.upcase }
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result = method_with_block_arguments(&make_upper)
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assert_equal __, result
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end
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# ------------------------------------------------------------------
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def method_with_explicit_block(&block)
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block.call(10)
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end
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def test_methods_can_take_an_explicit_block_argument
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assert_equal __, method_with_explicit_block { |n| n * 2 }
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add_one = lambda { |n| n + 1 }
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assert_equal __, method_with_explicit_block(&add_one)
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end
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end
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