Added testcases for keep-alive handling

* Added a dummy_server module to check connection count
* Added testcases for proxy and direct connections

tests/dummy_server.py

@@ -0,0 +1,46 @@
+import asyncore
+import threading
+import socket
+
+class HttpServer(threading.Thread):
+    def __init__(self, port):
+        threading.Thread.__init__(self)
+        self.dispatcher = HttpServerDispatcher(port)
+
+    def run(self):
+        asyncore.loop()
+
+    @property
+    def connection_count(self):
+        return self.dispatcher.connection_count
+
+    def close(self):
+        asyncore.close_all()
+
+class HttpServerDispatcher(asyncore.dispatcher):
+    def __init__(self, port):
+        asyncore.dispatcher.__init__(self)
+        self.connected = False
+        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.bind(('127.0.0.1', port))
+        self.listen(1)
+        self.connection_count = 0
+
+    def handle_accept(self):
+        self.connection_count += 1
+        self.handler = RequestHandler(self.accept()[0])
+
+    def handle_close(self):
+        self.close()
+
+
+class RequestHandler(asyncore.dispatcher_with_send):
+    def __init__(self, sock):
+        asyncore.dispatcher_with_send.__init__(self, sock)
+        self.response = ("HTTP/1.1 200 OK\r\n"
+                         "Connection: keep-alive\r\n"
+                         "Content-Length: 0\r\n\r\n")
+
+    def handle_read(self):
+        self.recv(1024)
+        self.send(self.response)

tests/test_keep_alive.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+import os
+import sys
+import unittest
+
+# Path hack.
+sys.path.insert(0, os.path.abspath('..'))
+import requests
+import dummy_server
+
+class KeepAliveTests(unittest.TestCase):
+    server_and_proxy_port = 1234
+    request_count = 2
+    url = 'http://localhost:{0}'.format(server_and_proxy_port)
+    proxies={'http': url}
+
+    def setUp(self):
+        self.session = requests.session()
+        self.proxy_server = dummy_server.HttpServer(self.server_and_proxy_port)
+        self.proxy_server.start()
+
+    def tearDown(self):
+        self.proxy_server.close()
+
+    def test_keep_alive_with_direct_connection(self):
+        self.make_requests()
+        self.check_each_request_are_in_same_connection()
+
+    def test_no_keep_alive_with_direct_connection(self):
+        self.disable_keep_alive_in_session()
+        self.make_requests()
+        self.check_each_request_are_in_different_connection()
+
+    def test_keep_alive_with_proxy_connection(self):
+        self.make_proxy_requests()
+        self.check_each_request_are_in_same_connection()
+
+    def test_no_keep_alive_with_proxy_connection(self):
+        self.disable_keep_alive_in_session()
+        self.make_proxy_requests()
+        self.check_each_request_are_in_different_connection()
+
+    def make_proxy_requests(self):
+        self.make_requests(self.proxies)
+
+    def make_requests(self, proxies=None):
+        for _ in xrange(self.request_count):
+            self.session.get(self.url, proxies=proxies).text
+
+    def check_each_request_are_in_same_connection(self):
+        """Keep-alive requests open a single connection to the server."""
+        self.assertEqual(self.proxy_server.connection_count, 1)
+
+    def check_each_request_are_in_different_connection(self):
+        """Keep-alive requests open a single connection to the server."""
+        self.assertEqual(self.proxy_server.connection_count, self.request_count)
+
+    def disable_keep_alive_in_session(self):
+        self.session.config['keep_alive'] = False
+
+
+if __name__ == '__main__':
+    unittest.main()