fix(uptime): Fix bug where regions are not created in shadow mode for new subscriptions (#85911)

We need to specify the mode for the region when creating it

Author: wedamija

src/sentry/uptime/subscriptions/subscriptions.py

@@ -282,7 +282,9 @@ def create_uptime_subscription(
     # Associate active regions with this subscription
     for region_config in get_active_regions():
         UptimeSubscriptionRegion.objects.create(
-            uptime_subscription=subscription, region_slug=region_config.slug
+            uptime_subscription=subscription,
+            region_slug=region_config.slug,
+            mode=region_config.mode,
         )
 
     create_remote_uptime_subscription.delay(subscription.id)

tests/sentry/uptime/subscriptions/test_subscriptions.py

@@ -105,6 +105,30 @@ def test_without_task(self):
         assert uptime_sub.interval_seconds == uptime_sub.interval_seconds
         assert uptime_sub.timeout_ms == timeout_ms
 
+    def test_regions(self):
+        with (
+            override_settings(
+                UPTIME_REGIONS=[
+                    UptimeRegionConfig(slug="active_region", name="active_region"),
+                    UptimeRegionConfig(slug="shadow_region", name="shadow_region"),
+                ]
+            ),
+            override_options(
+                {
+                    "uptime.checker-regions-mode-override": {
+                        "shadow_region": UptimeSubscriptionRegion.RegionMode.SHADOW
+                    }
+                }
+            ),
+        ):
+            uptime_sub = create_uptime_subscription("https://sentry.io", 300, 500)
+            assert [
+                (r.region_slug, r.mode) for r in uptime_sub.regions.all().order_by("region_slug")
+            ] == [
+                ("active_region", UptimeSubscriptionRegion.RegionMode.ACTIVE),
+                ("shadow_region", UptimeSubscriptionRegion.RegionMode.SHADOW),
+            ]
+
 
 class UpdateUptimeSubscriptionTest(UptimeTestCase):
     def test(self):