Repository: getmoto/moto (python)

Issue:
ECS list_services ClusterNotFoundException Not raised
## Reporting Bugs

Resource/Client:
**ECS**

Method:
**list_services**

When calling the `ecs` `list_services` with a cluster that does not exist (in moto) the API returns an empty list response.

Expected behavior:
It should raise `ClusterNotFoundException` if cluster_name is invalid.

Moto version: 4.1.0
Python: 3.9


Pull request description:
ECS: list_services() now throws correct error when providing unknown cluster
Fixes #5857 

Patch:
diff --git a/moto/ecs/models.py b/moto/ecs/models.py
index 7374ce403..5ce3aa848 100644
--- a/moto/ecs/models.py
+++ b/moto/ecs/models.py
@@ -808,7 +808,7 @@ class EC2ContainerServiceBackend(BaseBackend):
             service_region, zones, "ecs"
         )
 
-    def _get_cluster(self, name):
+    def _get_cluster(self, name: str) -> Cluster:
         # short name or full ARN of the cluster
         cluster_name = name.split("/")[-1]
 
@@ -1333,10 +1333,10 @@ class EC2ContainerServiceBackend(BaseBackend):
         return service
 
     def list_services(self, cluster_str, scheduling_strategy=None, launch_type=None):
-        cluster_name = cluster_str.split("/")[-1]
+        cluster = self._get_cluster(cluster_str)
         service_arns = []
         for key, service in self.services.items():
-            if cluster_name + ":" not in key:
+            if cluster.name + ":" not in key:
                 continue
 
             if (


Test patch:
diff --git a/tests/test_ecs/test_ecs_boto3.py b/tests/test_ecs/test_ecs_boto3.py
index 161212b01..94b81554e 100644
--- a/tests/test_ecs/test_ecs_boto3.py
+++ b/tests/test_ecs/test_ecs_boto3.py
@@ -701,6 +701,17 @@ def test_list_services():
     cluster1_fargate_services["serviceArns"][0].should.equal(test_ecs_service2_arn)
 
 
+@mock_ecs
+@pytest.mark.parametrize("args", [{}, {"cluster": "foo"}], ids=["no args", "unknown"])
+def test_list_unknown_service(args):
+    client = boto3.client("ecs", region_name="us-east-1")
+    with pytest.raises(ClientError) as exc:
+        client.list_services(**args)
+    err = exc.value.response["Error"]
+    err["Code"].should.equal("ClusterNotFoundException")
+    err["Message"].should.equal("Cluster not found.")
+
+
 @mock_ecs
 def test_describe_services():
     client = boto3.client("ecs", region_name="us-east-1")