Adding a sort order validation test

tests/integration/test_rest_catalog.py

@@ -61,3 +61,56 @@ def test_create_namespace_if_already_existing(catalog: RestCatalog) -> None:
     catalog.create_namespace_if_not_exists(TEST_NAMESPACE_IDENTIFIER)
 
     assert catalog.namespace_exists(TEST_NAMESPACE_IDENTIFIER)
+
+
+@pytest.mark.integration
+@pytest.mark.parametrize("catalog", [pytest.lazy_fixture("session_catalog")])
+def test_create_table_invalid_sort_order(catalog: RestCatalog) -> None:
+    from pyiceberg.catalog.rest import Endpoints
+    from pyiceberg.schema import Schema
+    from pyiceberg.types import LongType, NestedField
+
+    namespace = "default"
+    table_name = "test_invalid_sort_order"
+
+    # Ensure namespace exists
+    catalog.create_namespace_if_not_exists(namespace)
+
+    # Define a simple schema
+    schema = Schema(NestedField(1, "x", LongType()))
+
+    # Create the payload manually to bypass client-side validation
+    # We want a sort order that references a non-existent field ID (e.g., 9999)
+    payload = {
+        "name": table_name,
+        "schema": schema.model_dump(by_alias=True),
+        "write-order": {
+            "order-id": 1,
+            "fields": [
+                {
+                    "transform": "identity",
+                    "source-id": 9999,  # Non-existent field
+                    "direction": "asc",
+                    "null-order": "nulls-first",
+                }
+            ],
+        },
+        "stage-create": False,
+    }
+
+    # Send the request using the underlying session
+    # Endpoints.create_table is "namespaces/{namespace}/tables"
+    url = catalog.url(Endpoints.create_table, namespace=namespace)
+
+    response = catalog._session.post(url, json=payload)
+
+    assert response.status_code == 400
+    response_json = response.json()
+    response_json["error"].pop("stack", None)
+    assert response_json == {
+        "error": {
+            "message": "Cannot find source column for sort field: identity(9999) ASC NULLS FIRST",
+            "type": "ValidationException",
+            "code": 400,
+        }
+    }