Make query string comparison ignore order

Query string ordering is non-deterministic. This can cause tests to fail
in a non helpful way when we’re comparing two URLs. The values in the
query string can match, but the string won’t because the order is
different. This commit adds some code to split up the URL and check that
each part of it matches, rather than checking the thing as a whole.

tests/app/main/views/test_feedback.py

@@ -210,29 +210,44 @@ def test_passes_user_details_through_flow(
     {'feedback': 'blah', 'name': 'Fred'},
     {'feedback': 'blah'},
 ])
-@pytest.mark.parametrize('ticket_type, expected_response, things_expected_in_url, expected_error', [
-    (PROBLEM_TICKET_TYPE, 200, [], element.Tag),
-    (QUESTION_TICKET_TYPE, 302, ['thanks', 'email_address_provided=False', 'out_of_hours_emergency=False'], type(None)),
+@pytest.mark.parametrize('ticket_type, expected_response, expected_redirect, expected_error', [
+    (
+        PROBLEM_TICKET_TYPE,
+        200,
+        lambda: None,
+        element.Tag,
+    ),
+    (
+        QUESTION_TICKET_TYPE,
+        302,
+        partial(
+            url_for,
+            '.thanks',
+            email_address_provided=False,
+            out_of_hours_emergency=False,
+            _external=True,
+        ),
+        type(None),
+    ),
 ])
 def test_email_address_required_for_problems(
-    client,
+    client_request,
     mocker,
     data,
     ticket_type,
     expected_response,
-    things_expected_in_url,
+    expected_redirect,
     expected_error
 ):
     mocker.patch('app.main.views.feedback.zendesk_client')
-    response = client.post(
-        url_for('main.feedback', ticket_type=ticket_type),
-        data=data,
+    client_request.logout()
+    page = client_request.post(
+        'main.feedback',
+        ticket_type=ticket_type,
+        _data=data,
+        _expected_status=expected_response,
+        _expected_redirect=expected_redirect(),
     )
-    assert response.status_code == expected_response
-    # This is to work around non-deterministic query ordering in Flask url_for
-    for thing in things_expected_in_url:
-        assert thing in response.location
-    page = BeautifulSoup(response.data.decode('utf-8'), 'html.parser')
     assert isinstance(page.find('span', {'class': 'error-message'}), expected_error)