old_contents: from __future__ import absolute_import, division, print_function
  
  import unittest
  
  
  # Adapted from https://github.com/grpc/grpc/blob/master/examples/python/helloworld.
  class TestGrpcio(unittest.TestCase):
  
      def setUp(self):
          from concurrent import futures
          import grpc
          from . import helloworld_pb2, helloworld_pb2_grpc
  
          class Greeter(helloworld_pb2_grpc.GreeterServicer):
              def SayHello(self, request, context):
                  return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)
  
          self.server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
          helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), self.server)
          self.server.add_insecure_port('[::]:50051')
          self.server.start()
  
      def test_greeter(self):
          import grpc
          from . import helloworld_pb2, helloworld_pb2_grpc
  
          channel = grpc.insecure_channel('localhost:50051')
          stub = helloworld_pb2_grpc.GreeterStub(channel)
          response = stub.SayHello(helloworld_pb2.HelloRequest(name='world'))
          self.assertEqual("Hello, world!", response.message)
  
      def tearDown(self):
          self.server.stop(0)
  
new_contents: from __future__ import absolute_import, division, print_function
  
  import unittest
  
  
  # Adapted from https://github.com/grpc/grpc/blob/master/examples/python/helloworld.
  class TestGrpcio(unittest.TestCase):
  
      def setUp(self):
          from concurrent import futures
          import grpc
          from . import helloworld_pb2, helloworld_pb2_grpc
  
          class Greeter(helloworld_pb2_grpc.GreeterServicer):
              def SayHello(self, request, context):
                  return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)
  
          self.server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
          helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), self.server)
          self.port = self.server.add_insecure_port('localhost:0')
          self.assertTrue(self.port)
          self.server.start()
  
      def test_greeter(self):
          import grpc
          from . import helloworld_pb2, helloworld_pb2_grpc
  
          channel = grpc.insecure_channel('localhost:{}'.format(self.port))
          stub = helloworld_pb2_grpc.GreeterStub(channel)
          response = stub.SayHello(helloworld_pb2.HelloRequest(name='world'))
          self.assertEqual("Hello, world!", response.message)
  
      def tearDown(self):
          self.server.stop(0)
  
subject: Fix hardcoded port number in grpcio test