updated last check-in to last successful check-in

src/sentry/monitors/models.py

@@ -478,6 +478,13 @@ class Meta:
     def get_audit_log_data(self):
         return {"name": self.environment.name, "status": self.status, "monitor": self.monitor.name}
 
+    def get_last_successful_checkin(self):
+        return (
+            MonitorCheckIn.objects.filter(monitor_environment=self, status=CheckInStatus.OK)
+            .order_by("-date_added")
+            .first()
+        )
+
     def mark_failed(
         self, last_checkin=None, reason=MonitorFailure.UNKNOWN, occurrence_context=None
     ):
@@ -534,6 +541,12 @@ def mark_failed(
 
             occurrence_data = get_occurrence_data(reason, **occurrence_context)
 
+            # Get last successful check-in to show in evidence display
+            last_successful_checkin_timestamp = "None"
+            last_successful_checkin = self.get_last_successful_checkin()
+            if last_successful_checkin:
+                last_successful_checkin_timestamp = last_successful_checkin.date_added.isoformat()
+
             occurrence = IssueOccurrence(
                 id=uuid.uuid4().hex,
                 resource_id=None,
@@ -551,7 +564,9 @@ def mark_failed(
                     ),
                     IssueEvidence(name="Environment", value=self.environment.name, important=False),
                     IssueEvidence(
-                        name="Last check-in", value=last_checkin.isoformat(), important=False
+                        name="Last successful check-in",
+                        value=last_successful_checkin_timestamp,
+                        important=False,
                     ),
                 ],
                 evidence_data={},

tests/sentry/monitors/test_models.py

@@ -13,7 +13,9 @@
     MonitorCheckInTimeout,
 )
 from sentry.monitors.models import (
+    CheckInStatus,
     Monitor,
+    MonitorCheckIn,
     MonitorEnvironment,
     MonitorEnvironmentLimitsExceeded,
     MonitorFailure,
@@ -314,6 +316,13 @@ def test_mark_failed_default_params_issue_platform(self, mock_produce_occurrence
             status=monitor.status,
         )
 
+        successful_check_in = MonitorCheckIn.objects.create(
+            monitor=monitor,
+            monitor_environment=monitor_environment,
+            project_id=self.project.id,
+            status=CheckInStatus.OK,
+        )
+
         last_checkin = timezone.now()
         assert monitor_environment.mark_failed(last_checkin=last_checkin)
 
@@ -339,8 +348,8 @@ def test_mark_failed_default_params_issue_platform(self, mock_produce_occurrence
                         "important": False,
                     },
                     {
-                        "name": "Last check-in",
-                        "value": last_checkin.isoformat(),
+                        "name": "Last successful check-in",
+                        "value": successful_check_in.date_added.isoformat(),
                         "important": False,
                     },
                 ],
@@ -391,6 +400,12 @@ def test_mark_failed_with_reason_issue_platform(self, mock_produce_occurrence_to
             environment=self.environment,
             status=monitor.status,
         )
+        successful_check_in = MonitorCheckIn.objects.create(
+            monitor=monitor,
+            monitor_environment=monitor_environment,
+            project_id=self.project.id,
+            status=CheckInStatus.OK,
+        )
         last_checkin = timezone.now()
         assert monitor_environment.mark_failed(
             last_checkin=last_checkin,
@@ -420,8 +435,8 @@ def test_mark_failed_with_reason_issue_platform(self, mock_produce_occurrence_to
                         "important": False,
                     },
                     {
-                        "name": "Last check-in",
-                        "value": last_checkin.isoformat(),
+                        "name": "Last successful check-in",
+                        "value": successful_check_in.date_added.isoformat(),
                         "important": False,
                     },
                 ],
@@ -506,8 +521,8 @@ def test_mark_failed_with_missed_reason_issue_platform(self, mock_produce_occurr
                         "important": False,
                     },
                     {
-                        "name": "Last check-in",
-                        "value": last_checkin.isoformat(),
+                        "name": "Last successful check-in",
+                        "value": "None",
                         "important": False,
                     },
                 ],