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ruby_koans/src/about_symbols.rb
2010-09-21 16:05:02 -04:00

78 lines
2.1 KiB
Ruby

require File.expand_path(File.dirname(__FILE__) + '/edgecase')
class AboutSymbols < EdgeCase::Koan
def test_symbols_are_symbols
symbol = :ruby
assert_equal __(true), symbol.is_a?(Symbol)
end
def test_symbols_can_be_compared
symbol1 = :a_symbol
symbol2 = :a_symbol
symbol3 = :something_else
assert symbol1 == __(symbol2)
assert symbol1 != __(symbol3)
end
def test_identical_symbols_are_a_single_internal_object
symbol1 = :a_symbol
symbol2 = :a_symbol
assert symbol1.equal?(__(symbol2))
assert_equal __(symbol1.object_id), symbol2.object_id
end
def test_method_names_become_symbols
all_symbols = Symbol.all_symbols
assert_equal __(true), all_symbols.include?(:test_method_names_are_symbols)
end
RubyConstant = "What is the sound of one hand clapping?"
def test_constants_become_symbols
all_symbols = Symbol.all_symbols
assert_equal true, all_symbols.include?(__(:RubyConstant))
end
def test_symbols_can_be_made_from_strings
string = "catsAndDogs"
assert_equal __(:catsAndDogs), string.to_sym
end
def test_symbols_with_spaces_can_be_built
symbol = :"cats and dogs"
assert_equal symbol, __("cats and dogs").to_sym
end
def test_to_s_is_called_on_interpolated_symbols
symbol = :cats
string = "It is raining #{symbol} and dogs."
assert_equal __('It is raining cats and dogs.'), string
end
def test_symbols_are_not_strings
symbol = :ruby
assert_equal __(false), symbol.is_a?(String)
assert_equal __(false), symbol.eql?("ruby")
end
def test_symbols_do_not_have_string_methods
symbol = :not_a_string
assert_equal __(false), symbol.respond_to?(:each_char)
assert_equal __(false), symbol.respond_to?(:reverse)
end
# It's important to realize that symbols are not "immutable
# strings", though they are immutable. None of the
# interesting string operations are available on symbols.
def test_symbols_cannot_be_concatenated
# Exceptions will be pondered further father down the path
assert_raise(___(NoMethodError)) do
:cats + :dogs
end
end
end