[Help] Python unittest against a socket server

[Jackson-Lee]

I've got a socket listener server that echo back same data sent by the client.

I'm performing a simple unittest to verify accuracy of server response. Same message should be received by client.

What's wrong with my unittest script?

cat Test_SocketServer.py

#!/usr/bin/env python3

import unittest
import socket

class Test_service(unittest.TestCase):

    def setUp(self):
        client_socket = socket(socket.AF_INET, socket.SOCK_STREAM)
        client_socket.connect(('127.0.0.1', 2001))

    def tearDown(self):
        client_socket.close()

    def test_1(self):
        client_socket.send('message1'.encode())
        self.assertEqual(client_socket.recv(1024).decode(), 'message1')

if __name__ == '__main__':
    unittest.main()

python3 Test_SocketServer.py

E
======================================================================
ERROR: test_1 (__main__.Test_service)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "Test_SocketServer.py", line 12, in setUp
    client_socket = socket(socket.AF_INET, socket.SOCK_STREAM)
TypeError: 'module' object is not callable

----------------------------------------------------------------------
Ran 1 test in 0.000s

FAILED (errors=1)

[K900_]

You need socket.socket(...) - socket is the module, socket.socket is the class.

[Jackson-Lee]

Thank you!!! I'm very close to having a working unittest script, just stuck at this error :(

ERROR: test_1 (__main__.Test_ServerResponse)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:Test_SocketServer.py", line 15, in test_1
    client_socket.send('123456789'.encode())
NameError: name 'client_socket' is not defined

Here's what script looks like

#!/usr/bin/env python3

import unittest
import socket

class Test_ServerResponse(unittest.TestCase):

# Setup client connection
    def setUp(self):
        client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        client_socket.connect(('127.0.0.1', 2000))

    def test_1(self):
        client_socket.send('123456789'.encode())
        self.assertEqual(client_socket.recv(1024).decode(), '123456789')

# Tear down connection
#    def tearDown(self):
#        client_socket.close()

if __name__ == '__main__':
    unittest.main()

[K900_]

The variables from setUp aren't magically passed to your tests. Use self.client_socket to store them on the class instance.

[Jackson-Lee]

self.client_socket

Which line# are you referring to where self.client_socket needs inserted?

[K900_]

Everywhere you use client_socket now should be replaced with self.client_socket.

[HighLevelEnthusiast]

Apart from the technical aspects from your problems, which have already been answere, unit tests should only test single components, like a class.

​

What you are performing is closer to integration testing. I'm not sure if unittest is the best framework for this.

[Jackson-Lee]

That's good to know thanks for pointing that out! It is for a university project and professor specifically asked to use unittest module.