class RSpec::Rails::Matchers::BeANew

def attributes
  @attributes ||= {}
end

def attributes_match?(actual)
  attributes.stringify_keys.all? do |key, value|
    values_match?(value, actual.attributes[key])
  end
end

def failure_message
  [].tap do |message|
    unless actual.is_a?(expected) && actual.new_record?
      message << "expected #{actual.inspect} to be a new #{expected.inspect}"
    end
    unless attributes_match?(actual)
      describe_unmatched_attributes = surface_descriptions_in(unmatched_attributes)
      if unmatched_attributes.size > 1
        message << "attributes #{describe_unmatched_attributes.inspect} were not set on #{actual.inspect}"
      else
        message << "attribute #{describe_unmatched_attributes.inspect} was not set on #{actual.inspect}"
      end
    end
  end.join(' and ')
end

def initialize(expected)
  @expected = expected
end

def matches?(actual)
  @actual = actual
  actual.is_a?(expected) && actual.new_record? && attributes_match?(actual)
end

def unmatched_attributes
  attributes.stringify_keys.reject do |key, value|
    values_match?(value, actual.attributes[key])
  end
end

def with(expected_attributes)
  attributes.merge!(expected_attributes)
  self
end