move eventutil from urllib to requests (#700)

This resolves the 2018 TODO comment that suggests moving to requests.
I've preserved exact compatibility with the previous version here by
ensuring that the body is exactly the same, and I've re-enabled the test
for eventutil since it can now be mocked with responses.

tests/test_eventutil.py

@@ -1,8 +1,8 @@
 # coding: utf-8
 
 import datetime
+import json
 from decimal import Decimal
-from unittest import skip
 
 import responses
 from django.test import TransactionTestCase
@@ -22,13 +22,13 @@ def setUp(self):
             datetime=datetime.datetime(2018, 1, 1),
         )
         self.postback = PostbackURL.objects.create(
-            event=self.event, url='https://example.com'
+            event=self.event,
+            url='https://example.com',
         )
 
-    @skip("This test only works with requests :')")
     @responses.activate
     def test_request_made(self):
-        responses.add(responses.GET, 'https://example.com', status=200)
+        responses.post('https://example.com', status=200)
 
         donation = Donation.objects.create(
             timereceived=datetime.datetime(2018, 1, 1),
@@ -37,13 +37,24 @@ def test_request_made(self):
             domain='PAYPAL',
             donor=self.donor,
             event=self.event,
+            transactionstate='COMPLETED',
         )
 
         eventutil.post_donation_to_postbacks(donation)
 
         assert len(responses.calls) == 1
-        assert (
-            responses.calls[0].request.url
-            == 'https://example.com/?comment=&amount=1.5&timereceived=2018-01-01+00%3A00%3A00&donor__visibility=FIRST&domain=PAYPAL&id=1&donor__visiblename=%28No+Name%29'
-        )
-        assert responses.calls[0].response.status_code == 200
+        resp = responses.calls[0]
+        assert resp.request.url == 'https://example.com/'
+        assert json.loads(resp.request.body) == {
+            'id': donation.id,
+            'event': donation.event_id,
+            'timereceived': '2018-01-01 00:00:00',
+            'comment': '',
+            'amount': 1.5,
+            'donor__visibility': 'FIRST',
+            'donor__visiblename': '(No Name)',
+            'new_total': 1.5,
+            'domain': 'PAYPAL',
+            'bids': [],
+        }
+        assert resp.response.status_code == 200

tracker/eventutil.py

@@ -1,7 +1,7 @@
 import json
 import traceback
-import urllib.request
 
+import requests
 from asgiref.sync import async_to_sync
 from channels.layers import get_channel_layer
 from django.core import serializers
@@ -12,8 +12,6 @@
 import tracker.viewutil as viewutil
 from tracker.consumers.processing import broadcast_new_donation_to_processors
 
-# TODO: this is 2018, we ought to be using requests
-
 
 def post_donation_to_postbacks(donation):
     event_donations = filters.run_model_query('donation', {'event': donation.event.id})
@@ -57,13 +55,12 @@ def post_donation_to_postbacks(donation):
 
         postbacks = models.PostbackURL.objects.filter(event=donation.event)
         for postback in postbacks:
-            opener = urllib.request.build_opener()
-            req = urllib.request.Request(
+            requests.post(
                 postback.url,
-                data_json,
+                data=data_json,
                 headers={'Content-Type': 'application/json; charset=utf-8'},
+                timeout=5,
             )
-            opener.open(req, timeout=5)
     except Exception:
         viewutil.tracker_log(
             'postback_url', traceback.format_exc(), event=donation.event