Rspec: Negation Matcher - description_when_negated

gistfile1.rb

expect([1, 2, 3]).to ~include(3)


class Negation < BaseMatcher
  def failure_message
    matcher.failure_message_when_negated
  end
end


class Include < BaseMatcher
  def failure_message_when_negated
    improve_hash_formatting(super) # this is the issue
  end
  
  def description_when_negated
    "not #{description}" # or what ever you like...
  end
end


class BaseMatcher
  def failure_message_when_negated
    assert_ivars :@actual
    if respond_to?(:description_when_negated)
      "expected #{@actual.inspect} to #{description_when_negated}"
    else
      "expected #{@actual.inspect} to not #{description}"
    end
  end
end