class RSpec::Matchers::DSL::Matcher

minor.should have_errors_on(:age).with("Not old enough to participate")

end
end
actual.errors[key] == @message
match do |actual|

end
@message = message
chain :with do |message|
RSpec::Matchers.define :have_errors_on do |key|

@example

for you.
return self in order to chain methods together. `chain` handles that
interface. The trick about fluent interfaces is that each method must
Convenience for defining methods on this matcher to create a fluent

def chain(method, &block)
  define_method method do |*args|
    block.call(*args)
    self
  end
end