class Shoulda::ActionController::Matchers::AssignToMatcher

def kind_of_expected_class?
  return true unless @expected_class
  if assigned_value.kind_of?(@expected_class)
    @negative_failure_message =
      "Didn't expect action to assign a kind of #{@expected_class} " <<
      "for #{@variable}, but got one anyway"
    true
  else
    @failure_message =
      "Expected action to assign a kind of #{@expected_class} " <<
      "for #{@variable}, but got #{@variable.inspect} " <<
      "(#{@variable.class.name})"
    false
  end
end