old_contents: #!/usr/bin/env python
  #encoding: utf8
  import unittest, rostest
  import rosnode, rospy
  import time
  from pimouse_ros.msg import LightSensorValues
  
  class LightsensorTest(unittest.TestCase):
  	def setUp(self):
  		self.count = 0
  		rospy.Subscriber('/lightsensors', LightSensorValues, self.callback)
  		self.values = LightSensorValues()
  
  	def callback(self, data):
  		self.count +=1
  		self.values = data
  
  	def check_values(self, lf, ls, rs, rf):
  		vs = self.values
  		self.assertEqual(vs.left_forward, lf, "different value: left_forward")
  		self.assertEqual(vs.left_side, ls, "different value: left_side")
  		self.assertEqual(vs.right_side, rs, "different value: right_side")
  		self.assertEqual(vs.right_forward, rf, "different value: right_forward")
  		self.assertEqual(vs.sum_all, lf+ls+rs+rf, "different value: sum_all")
  		self.assertEqual(vs.left_forward + vs.right_forward, lf+rf, "different value: sum_forward")
  		
  	def test_node_exist(self):
  		nodes = rosnode.get_node_names()
  		self.assertIn('/lightsensors', nodes, "node does not exist")
  	
  	def test_get_value(self):
  		rospy.set_param('lightsensors_freq',10)
  		time.sleep(2)
  		with open("/dev/rtlightsensor0","w") as f:
  			f.write("-1 0 123 4321\n")
  
  		time.sleep(3)
  		self.assertFalse(self.count == 0, " cannnot subscribe the topic")
  		self.check_values(4321,123,0,-1)
  
  	def test_change_parameter(self):
  		rospy.set_param('lightsensors_freq',1)
  		time.sleep(2)
  		c_prev = self.count
  		time.sleep(3)
  		self.assertTrue(self.count < c_prev + 4, "freq does not change")
  		self.assertFalse(self.count == c_prev, "subscriber is stopped")
  
  if __name__ == "__main__":
  	time.sleep(3)
  	rospy.init_node('travis_test_lightsensors')
  	rostest.rosrun('pimouse_ros', 'travis_test_lightsensors', LightsensorTest)
  	
  
  
new_contents: #!/usr/bin/env python
  #encoding: utf8
  import unittest, rostest
  import rosnode, rospy
  import time
  from pimouse_ros.msg import LightSensorValues
  
  class LightsensorTest(unittest.TestCase):
  	def setUp(self):
  		self.count = 0
  		rospy.Subscriber('/lightsensors', LightSensorValues, self.callback)
  		self.values = LightSensorValues()
  
  	def callback(self, data):
  		self.count +=1
  		self.values = data
  
  	def check_values(self, lf, ls, rs, rf):
  		vs = self.values
  		self.assertEqual(vs.left_forward, lf, "different value: left_forward")
  		self.assertEqual(vs.left_side, ls, "different value: left_side")
  		self.assertEqual(vs.right_side, rs, "different value: right_side")
  		self.assertEqual(vs.right_forward, rf, "different value: right_forward")
  		self.assertEqual(vs.sum_all, lf+ls+rs+rf, "different value: sum_all")
  		self.assertEqual(vs.sum_forward, lf+rf, "different value: sum_forward")
  		
  	def test_node_exist(self):
  		nodes = rosnode.get_node_names()
  		self.assertIn('/lightsensors', nodes, "node does not exist")
  	
  	def test_get_value(self):
  		rospy.set_param('lightsensors_freq',10)
  		time.sleep(2)
  		with open("/dev/rtlightsensor0","w") as f:
  			f.write("-1 0 123 4321\n")
  
  		time.sleep(3)
  		self.assertFalse(self.count == 0, " cannnot subscribe the topic")
  		self.check_values(4321,123,0,-1)
  
  	def test_change_parameter(self):
  		rospy.set_param('lightsensors_freq',1)
  		time.sleep(2)
  		c_prev = self.count
  		time.sleep(3)
  		self.assertTrue(self.count < c_prev + 4, "freq does not change")
  		self.assertFalse(self.count == c_prev, "subscriber is stopped")
  
  if __name__ == "__main__":
  	time.sleep(3)
  	rospy.init_node('travis_test_lightsensors')
  	rostest.rosrun('pimouse_ros', 'travis_test_lightsensors', LightsensorTest)
  	
  
  
subject: fix test code