Fix bug checking forwarding ports. Give better debug message (include protocol).

tools/telemetry/telemetry/core/forwarders/do_nothing_forwarder_unittest.py

Index: tools/telemetry/telemetry/core/forwarders/do_nothing_forwarder_unittest.py
diff --git a/tools/telemetry/telemetry/core/forwarders/do_nothing_forwarder_unittest.py b/tools/telemetry/telemetry/core/forwarders/do_nothing_forwarder_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..174ab509f9f6bdcc9d176a5ea2137a4f17be36bb
--- /dev/null
+++ b/tools/telemetry/telemetry/core/forwarders/do_nothing_forwarder_unittest.py
@@ -0,0 +1,71 @@
+# Copyright 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import unittest
+
+from telemetry.core import forwarders
+from telemetry.core import util
+from telemetry.core.forwarders import do_nothing_forwarder
+
+
+class TestDoNothingForwarder(do_nothing_forwarder.DoNothingForwarder):
+  """Override _WaitForConnect to avoid actual socket connection."""
+
+  def __init__(self, port_pairs):
+    self.connected_addresses = []
+    super(TestDoNothingForwarder, self).__init__(port_pairs)
+
+  def _WaitForConnectionEstablished(self, address, timeout):
+    self.connected_addresses.append(address)
+
+
+class TestErrorDoNothingForwarder(do_nothing_forwarder.DoNothingForwarder):
+  """Simulate a connection error."""
+
+  def _WaitForConnectionEstablished(self, address, timeout):
+    raise util.TimeoutException
+
+
+class CheckPortPairsTest(unittest.TestCase):
+  def testChecksOnlyHttpHttps(self):
+    port_pairs = forwarders.PortPairs(
+        http=forwarders.PortPair(80, 80),
+        https=forwarders.PortPair(443, 443),
+        dns=forwarders.PortPair(53, 53))
+    f = TestDoNothingForwarder(port_pairs)
+    expected_connected_addresses = [
+        ('127.0.0.1', 80),
+        ('127.0.0.1', 443),
+        # Port 53 is skipped because it is UDP and does not support connections.
+        ]
+    self.assertEqual(expected_connected_addresses, f.connected_addresses)
+
+  def testNoDnsStillChecksHttpHttps(self):
+    port_pairs = forwarders.PortPairs(
+        http=forwarders.PortPair(5566, 5566),
+        https=forwarders.PortPair(7788, 7788),
+        dns=None)
+    f = TestDoNothingForwarder(port_pairs)
+    expected_connected_addresses = [
+        ('127.0.0.1', 5566),
+        ('127.0.0.1', 7788),
+        ]
+    self.assertEqual(expected_connected_addresses, f.connected_addresses)
+
+  def testPortMismatchRaisesPortsMismatchError(self):
+    # The do_nothing_forward cannot forward from one port to another.
+    port_pairs = forwarders.PortPairs(
+        http=forwarders.PortPair(80, 80),
+        https=forwarders.PortPair(8443, 443),
+        dns=None)
+    with self.assertRaises(do_nothing_forwarder.PortsMismatchError):
+      TestDoNothingForwarder(port_pairs)
+
+  def testConnectionTimeoutRaisesConnectionError(self):
+    port_pairs = forwarders.PortPairs(
+        http=forwarders.PortPair(80, 80),
+        https=forwarders.PortPair(8443, 443),
+        dns=None)
+    with self.assertRaises(do_nothing_forwarder.ConnectionError):
+      TestErrorDoNothingForwarder(port_pairs)