require 'abstract_unit' module TestApiFileUtils def file_path() File.expand_path(__FILE__) end def file_data() @data ||= File.open(file_path, 'rb') { |f| f.read } end end class DataStreamingApiController < ActionController::API include TestApiFileUtils def one; end def two send_data(file_data, {}) end end class DataStreamingApiTest < ActionController::TestCase include TestApiFileUtils tests DataStreamingApiController def test_data response = process('two') assert_kind_of String, response.body assert_equal file_data, response.body end end