mspec/lib/mspec/matchers/signed_zero.rb
class SignedZeroMatcher
def initialize(expected_sign)
@expected_sign = expected_sign
end
def matches?(actual)
@actual = actual
(1.0/actual).infinite? == @expected_sign
end
def failure_message
["Expected #{@actual}", "to be #{"-" if @expected_sign == -1}0.0"]
end
def negative_failure_message
["Expected #{@actual}", "not to be #{"-" if @expected_sign == -1}0.0"]
end
end
class Object
def be_positive_zero
SignedZeroMatcher.new(1)
end
def be_negative_zero
SignedZeroMatcher.new(-1)
end
end