IHS-75: Fix cardinality many error message

changelog/174.fixed.md

@@ -0,0 +1 @@
+Improve error message when a single node is passed to a cardinality-many relationship.

infrahub_sdk/node/relationship.py

@@ -163,7 +163,11 @@ def __init__(
                     RelatedNode(name=name, client=self.client, branch=self.branch, schema=schema, data=item)
                 )
         else:
-            raise ValueError(f"Unexpected format for {name} found a {type(data)}, {data}")
+            raise ValueError(
+                f"Relationship '{name}' expects a list of nodes (cardinality many), "
+                f"but received a single {type(data).__name__}. "
+                f"Wrap the value in a list, e.g. {name}=[value]."
+            )
 
     def __getitem__(self, item: int) -> RelatedNode:
         return self.peers[item]  # type: ignore[return-value]
@@ -296,7 +300,11 @@ def __init__(
                     RelatedNodeSync(name=name, client=self.client, branch=self.branch, schema=schema, data=item)
                 )
         else:
-            raise ValueError(f"Unexpected format for {name} found a {type(data)}, {data}")
+            raise ValueError(
+                f"Relationship '{name}' expects a list of nodes (cardinality many), "
+                f"but received a single {type(data).__name__}. "
+                f"Wrap the value in a list, e.g. {name}=[value]."
+            )
 
     def __getitem__(self, item: int) -> RelatedNodeSync:
         return self.peers[item]  # type: ignore[return-value]

tests/unit/sdk/test_node.py

@@ -312,6 +312,36 @@ async def test_init_node_data_graphql(
     assert node.primary_tag.typename == "BuiltinTag"
 
 
+@pytest.mark.parametrize("client_type", client_types)
+async def test_cardinality_many_requires_list(
+    client: InfrahubClient, location_schema: NodeSchemaAPI, client_type: str
+) -> None:
+    data = {
+        "name": {"value": "JFK1"},
+        "tags": {"id": "pppppppp"},
+    }
+    with pytest.raises(ValueError, match=r"expects a list of nodes"):
+        if client_type == "standard":
+            InfrahubNode(client=client, schema=location_schema, data=data)
+        else:
+            InfrahubNodeSync(client=client, schema=location_schema, data=data)
+
+
+@pytest.mark.parametrize("client_type", client_types)
+async def test_cardinality_many_accepts_list(
+    client: InfrahubClient, location_schema: NodeSchemaAPI, client_type: str
+) -> None:
+    data = {
+        "name": {"value": "JFK1"},
+        "tags": [{"id": "aaaaaa"}, {"id": "bbbb"}],
+    }
+    if client_type == "standard":
+        node = InfrahubNode(client=client, schema=location_schema, data=data)
+    else:
+        node = InfrahubNodeSync(client=client, schema=location_schema, data=data)
+    assert len(node.tags.peers) == 2
+
+
 @pytest.mark.parametrize("client_type", client_types)
 async def test_query_data_no_filters_property(
     clients: BothClients, location_schema: NodeSchemaAPI, client_type: str