BUGFIX: re adding feature flag after deleting

posthog/api/feature_flag.py

@@ -46,7 +46,10 @@ def create(self, validated_data: Dict, *args: Any, **kwargs: Any) -> FeatureFlag
         try:
             feature_flag = super().create(validated_data)
         except IntegrityError:
-            raise serializers.ValidationError("This key already exists.", code="key-exists")
+            if self.perform_destroy(validated_data["key"]):
+                feature_flag = super().create(validated_data)
+            else:
+                raise serializers.ValidationError("This key already exists.", code="key-exists")
 
         return feature_flag
 
@@ -56,6 +59,15 @@ def update(self, instance: FeatureFlag, validated_data: Dict, *args: Any, **kwar
         except IntegrityError:
             raise serializers.ValidationError("This key already exists.", code="key-exists")
 
+    def perform_destroy(self, key: str) -> bool:
+        featureFlag = FeatureFlag.objects.all().filter(deleted=True, key=key).first()
+
+        if featureFlag:
+            featureFlag.delete()
+            return True
+
+        return False
+
 
 class FeatureFlagViewSet(AnalyticsDestroyModelMixin, viewsets.ModelViewSet):
     queryset = FeatureFlag.objects.all()