refactor: streamline cache access in minor_trace_chemistry_transfer

Author: jirhiker

tests/test_minor_trace_chemistry_transfer.py

@@ -6,6 +6,7 @@
 
 
 def test_row_to_dict_includes_wclab_id():
+    # Bypass __init__ so we can stub the cache without hitting the DB.
     transfer = MinorTraceChemistryTransferer.__new__(MinorTraceChemistryTransferer)
     sample_pt_id = uuid.uuid4()
     transfer._sample_pt_ids = {sample_pt_id}

transfers/minor_trace_chemistry_transfer.py

@@ -177,10 +177,7 @@ def _row_to_dict(self, row) -> Optional[dict[str, Any]]:
             return None
 
         # Look up Integer FK from cache
-        cache = getattr(self, "_sample_info_cache", None)
-        if cache is None:
-            cache = {}
-        chemistry_sample_info_id = cache.get(legacy_sample_pt_id)
+        chemistry_sample_info_id = self._sample_info_cache.get(legacy_sample_pt_id)
         if chemistry_sample_info_id is None:
             self._capture_error(
                 legacy_sample_pt_id,