FlexMockRails模拟测试工具

FlexMock是一个比较流行的针对Rails单元测试的Mock工具，

安装方法：$ gem install flexmock

代码示例：

  require 'test/unit'
  require 'flexmock/test_unit'

  class TemperatureSampler
    def initialize(sensor)
      @sensor = sensor
    end

    def average_temp
      total = (0...3).collect {
        @sensor.read_temperature
      }.inject { |i, s| i + s }
      total / 3.0
    end
  end

  class TestTemperatureSampler < Test::Unit::TestCase
    def test_sensor_can_average_three_temperature_readings
      sensor = flexmock("temp")
      sensor.should_receive(:read_temperature).times(3).
        and_return(10, 12, 14)

      sampler = TemperatureSampler.new(sensor)
      assert_equal 12, sampler.average_temp
    end
  end