module ActionController::SerializationAssertions

def assert_serializer(options = {}, message = nil)



assert_serializer nil
# assert that no serializer was rendered

assert_serializer %r{\APost.+\Z}
# assert that the rendered serializer starts with "Post"

assert_serializer :post_serializer
# assert that the "PostSerializer" serializer was rendered

assert_serializer PostSerializer
# assert that the instance of PostSerializer was rendered

assert_serializer "PostSerializer"
# assert that the "PostSerializer" serializer was rendered

Asserts that the request was rendered with the appropriate serializers. 
def assert_serializer(options = {}, message = nil)
  # Force body to be read in case the template is being streamed.
  response.body
  rendered = @serializers
  msg = message || "expecting <#{options.inspect}> but rendering with <#{rendered.keys}>"
  matches_serializer = case options
                       when lambda { |options| options.kind_of?(Class) && options < ActiveModel::Serializer }
                         rendered.any? do |serializer, count|
                           options.name == serializer
                         end
                       when Symbol
                         options = options.to_s.camelize
                         rendered.any? do |serializer, count|
                           serializer == options
                         end
                       when String
                         !options.empty? && rendered.any? do |serializer, count|
                           serializer == options
                         end
                       when Regexp
                         rendered.any? do |serializer, count|
                           serializer.match(options)
                         end
                       when NilClass
                         rendered.blank?
                       else
                         raise ArgumentError, "assert_serializer only accepts a String, Symbol, Regexp, ActiveModel::Serializer, or nil"
                       end
  assert matches_serializer, msg
end

def process(*args) 

def process(*args)
  @serializers = Hash.new(0)
  super
end

def setup_serialization_subscriptions 

def setup_serialization_subscriptions
  @serializers = Hash.new(0)
  ActiveSupport::Notifications.subscribe("!serialize.active_model_serializers") do |name, start, finish, id, payload|
    serializer = payload[:serializer]
    @serializers[serializer] += 1
  end
end

def teardown_serialization_subscriptions 

def teardown_serialization_subscriptions
  ActiveSupport::Notifications.unsubscribe("!serialize.active_model_serializers")
end