Tweak for single structure testing with check_response

- If a single ID is passed as a string, validate the request as a single
entry request
- If a single ID is passed within a list, validate it is a multi-entry
request that only returns one result

tests/server/conftest.py

@@ -102,25 +102,38 @@ def inner(
 
 @pytest.fixture
 def check_response(get_good_response):
-    """Fixture to check "good" response"""
+    """Check response matches expectations for a given request.
+
+    Parameters:
+        request: The request to check.
+        expected_ids: A list of IDs, or a single ID to check
+            the response for.
+        page_limit: The number of results expected per page.
+        expected_return: The number of results expected to be returned.
+        expected_as_is: Whether to enforce the order of the IDs.
+        expected_warnings: A list of expected warning messages.
+        server: The type of server to test, or the actual test client class.
+
+    """
     from typing import List
     from optimade.server.config import CONFIG
     from .utils import OptimadeTestClient
 
     def inner(
         request: str,
-        expected_ids: List[str],
+        expected_ids: Union[str, List[str]],
         page_limit: int = CONFIG.page_limit,
         expected_return: int = None,
         expected_as_is: bool = False,
         expected_warnings: List[Dict[str, str]] = None,
         server: Union[str, OptimadeTestClient] = "regular",
     ):
         response = get_good_response(request, server)
-        if isinstance(response["data"], dict):
-            response_ids = [response["data"]["id"]]
-        else:
-            response_ids = [struct["id"] for struct in response["data"]]
+        if isinstance(expected_ids, str):
+            expected_ids = [expected_ids]
+            response["data"] = [response["data"]]
+
+        response_ids = [struct["id"] for struct in response["data"]]
 
         if expected_return is not None:
             assert expected_return == response["meta"]["data_returned"]

tests/server/routers/test_structures.py

@@ -73,7 +73,7 @@ def test_check_response_single_structure(check_response):
     """Tests whether check_response also handles single endpoint queries correctly."""
 
     test_id = "mpf_1"
-    expected_ids = ["mpf_1"]
+    expected_ids = "mpf_1"
     request = f"/structures/{test_id}?response_fields=chemical_formula_reduced"
     check_response(request, expected_ids=expected_ids)