Change slack URL to be built the same as other engine URLs (#280)

* Change slack login url to be built the same way as other engine urls

* Fix tests

* Change how to override base url in create_engine_url

* Change how to override base url in create_engine_url

engine/apps/alerts/tests/test_alert_receiver_channel.py

@@ -5,6 +5,7 @@ import pytest
 from django.urls import reverse
 
 from apps.alerts.models import AlertReceiveChannel
+from common.api_helpers.utils import create_engine_url
 
 
 @pytest.mark.django_db
@@ -26,11 +27,7 @@ def test_integration_url(make_organization, make_alert_receive_channel, url, set
         kwargs={"alert_channel_key": alert_receive_channel.token},
     )
 
-    # remove trailing / if present
-    if url[-1] == "/":
-        url = url[:-1]
-
-    assert alert_receive_channel.integration_url == f"{url}{path}"
+    assert alert_receive_channel.integration_url == create_engine_url(path)
 
 
 @pytest.mark.django_db

engine/apps/social_auth/live_setting_django_strategy.py

@@ -7,6 +7,7 @@ from django.utils.functional import Promise
 from social_django.strategy import DjangoStrategy
 
 from apps.base.utils import live_settings
+from common.api_helpers.utils import create_engine_url
 
 logger = logging.getLogger(__name__)
 
@@ -37,9 +38,9 @@ class LiveSettingDjangoStrategy(DjangoStrategy):
         Overridden DjangoStrategy's method to substitute and force the host value from ENV
         """
         if live_settings.SLACK_INSTALL_RETURN_REDIRECT_HOST is not None and path is not None:
-            return live_settings.SLACK_INSTALL_RETURN_REDIRECT_HOST + path
+            return create_engine_url(path, override_base=live_settings.SLACK_INSTALL_RETURN_REDIRECT_HOST)
         if settings.SLACK_INSTALL_RETURN_REDIRECT_HOST is not None and path is not None:
-            return settings.SLACK_INSTALL_RETURN_REDIRECT_HOST + path
+            return create_engine_url(path, override_base=settings.SLACK_INSTALL_RETURN_REDIRECT_HOST)
         if self.request:
             return self.request.build_absolute_uri(path)
         else:

engine/common/api_helpers/utils.py

@@ -54,8 +54,10 @@ def validate_ical_url(url):
     return None
 
 
-def create_engine_url(path):
+def create_engine_url(path, override_base=None):
     base = settings.BASE_URL
+    if override_base:
+        base = override_base
     if not base.endswith("/"):
         base += "/"
     trimmed_path = path.lstrip("/")