Handle exceptions in event dispatcher (#30)

aliabbasrizvi · web-flow · commit e9871307ee9f · 2016-09-30T11:44:43.000-07:00
diff --git a/optimizely/event_dispatcher.py b/optimizely/event_dispatcher.py
@@ -1,6 +1,9 @@
 import json
+import logging
 import requests
 
+from requests import exceptions as request_exception
+
 from .helpers import enums
 
 REQUEST_TIMEOUT = 10
@@ -15,7 +18,11 @@ def dispatch_event(event):
     Args:
       event: Object holding information about the request to be dispatched to the Optimizely backend.
     """
-    if event.http_verb == enums.HTTPVerbs.GET:
-      requests.get(event.url, params=event.params, timeout=REQUEST_TIMEOUT)
-    elif event.http_verb == enums.HTTPVerbs.POST:
-      requests.post(event.url, data=json.dumps(event.params), headers=event.headers, timeout=REQUEST_TIMEOUT)
+
+    try:
+      if event.http_verb == enums.HTTPVerbs.GET:
+        requests.get(event.url, params=event.params, timeout=REQUEST_TIMEOUT)
+      elif event.http_verb == enums.HTTPVerbs.POST:
+        requests.post(event.url, data=json.dumps(event.params), headers=event.headers, timeout=REQUEST_TIMEOUT)
+    except request_exception.RequestException as error:
+      logging.error('Dispatch event failed. Error: %s' % str(error))
diff --git a/tests/test_event_dispatcher.py b/tests/test_event_dispatcher.py
@@ -1,6 +1,7 @@
 import mock
 import json
 import unittest
+from requests import exceptions as request_exception
 
 from optimizely import event_builder
 from optimizely import event_dispatcher
@@ -43,3 +44,25 @@ def test_dispatch_event__post_request(self):
     mock_request_post.assert_called_once_with(url, data=json.dumps(params),
                                               headers={'Content-Type': 'application/json'},
                                               timeout=event_dispatcher.REQUEST_TIMEOUT)
+
+  def test_dispatch_event__handle_request_exception(self):
+    """ Test that dispatch event handles exceptions and logs error. """
+
+    url = 'https://www.optimizely.com'
+    params = {
+      'accountId': '111001',
+      'eventName': 'test_event',
+      'eventEntityId': '111028',
+      'visitorId': 'oeutest_user'
+    }
+    event = event_builder.Event(url, params, http_verb='POST', headers={'Content-Type': 'application/json'})
+
+    with mock.patch('requests.post',
+                    side_effect=request_exception.RequestException('Failed Request')) as mock_request_post,\
+        mock.patch('logging.error') as mock_log_error:
+      event_dispatcher.EventDispatcher.dispatch_event(event)
+
+    mock_request_post.assert_called_once_with(url, data=json.dumps(params),
+                                              headers={'Content-Type': 'application/json'},
+                                              timeout=event_dispatcher.REQUEST_TIMEOUT)
+    mock_log_error.assert_called_once_with('Dispatch event failed. Error: Failed Request')
