mspec/lib/mspec/matchers/infinity.rb
class InfinityMatcher
def initialize(expected_sign)
@expected_sign = expected_sign
end
def matches?(actual)
@actual = actual
@actual.kind_of?(Float) && @actual.infinite? == @expected_sign
end
def failure_message
["Expected #{@actual}", "to be #{"-" if @expected_sign == -1}Infinity"]
end
def negative_failure_message
["Expected #{@actual}", "not to be #{"-" if @expected_sign == -1}Infinity"]
end
end
class Object
def be_positive_infinity
InfinityMatcher.new(1)
end
def be_negative_infinity
InfinityMatcher.new(-1)
end
end