test tcpclient.source_address, increase coverage

test/test_tcp.py

@@ -1,4 +1,4 @@
-import cStringIO, Queue, time, socket
+import cStringIO, Queue, time, socket, random
 from netlib import tcp, certutils, test
 import mock
 import tutils
@@ -24,6 +24,12 @@ class EchoHandler(tcp.BaseHandler):
         self.wfile.flush()
 
 
+class ClientPeernameHandler(tcp.BaseHandler):
+    def handle(self):
+        self.wfile.write(str(self.connection.getpeername()))
+        self.wfile.flush()
+
+
 class CertHandler(tcp.BaseHandler):
     sni = None
     def handle_sni(self, connection):
@@ -74,6 +80,22 @@ class TestServer(test.ServerTestBase):
         assert c.rfile.readline() == testval
 
 
+class TestServerBind(test.ServerTestBase):
+    handler = ClientPeernameHandler
+
+    def test_bind(self):
+        """ Test to bind to a given random port. Try again if the random port turned out to be blocked. """
+        for i in range(20):
+            random_port = random.randrange(1024, 65535)
+            try:
+                c = tcp.TCPClient("127.0.0.1", self.port, source_address=("127.0.0.1", random_port))
+                c.connect()
+                assert c.rfile.readline() == str(("127.0.0.1", random_port))
+                return
+            except tcp.NetLibError: # port probably already in use
+                pass
+
+
 class TestServerIPv6(test.ServerTestBase):
     handler = EchoHandler
     use_ipv6 = True