Match RemoteButler.get() exceptions to Direct

It turns out that DirectButler typically throws two different exceptions from get():
1. DatasetNotFoundError if the dataset can't be found in registry
2.  FileNotFoundError if the file itself cannot be found or under some other error conditions (some of which involve not being able to find the dataset in registry.)

Added test coverage for case #1, and fixed RemoteButler to comply with it.  Loosened the tests for some unusual error conditions to allow either of the two exception types, because RemoteButler doesn't have enough information available to replicate the DirectButler behavior.

python/lsst/daf/butler/remote_butler/_remote_butler.py

@@ -264,10 +264,7 @@ def get(
         **kwargs: Any,
     ) -> Any:
         # Docstring inherited.
-        try:
-            model = self._get_file_info(datasetRefOrType, dataId, collections, kwargs)
-        except DatasetNotFoundError as e:
-            raise FileNotFoundError(str(e)) from e
+        model = self._get_file_info(datasetRefOrType, dataId, collections, kwargs)
 
         ref = DatasetRef.from_simple(model.dataset_ref, universe=self.dimensions)
         # If the caller provided a DatasetRef, they may have overridden the

tests/test_butler.py

@@ -86,6 +86,7 @@ def mock_aws(*args: Any, **kwargs: Any) -> Any:  # type: ignore[no-untyped-def]
     Config,
     DataCoordinate,
     DatasetExistence,
+    DatasetNotFoundError,
     DatasetRef,
     DatasetType,
     FileDataset,
@@ -287,6 +288,10 @@ def runPutGetTest(self, storageClass: StorageClass, datasetTypeName: str) -> But
         metric = makeExampleMetrics()
         dataId = butler.registry.expandDataId({"instrument": "DummyCamComp", "visit": 423})
 
+        # Dataset should not exist if we haven't added it
+        with self.assertRaises(DatasetNotFoundError):
+            butler.get(datasetTypeName, dataId)
+
         # Put and remove the dataset once as a DatasetRef, once as a dataId,
         # and once with a DatasetType
 
@@ -413,7 +418,7 @@ def runPutGetTest(self, storageClass: StorageClass, datasetTypeName: str) -> But
                     kwargs = {}  # Prevent warning from being issued.
                 self.assertFalse(butler.exists(*args, **kwargs))
                 # get() should still fail.
-                with self.assertRaises(FileNotFoundError):
+                with self.assertRaises((FileNotFoundError, DatasetNotFoundError)):
                     butler.get(ref)
                 # Registry shouldn't be able to find it by dataset_id anymore.
                 self.assertIsNone(butler.get_dataset(ref.id))
@@ -496,7 +501,7 @@ def runPutGetTest(self, storageClass: StorageClass, datasetTypeName: str) -> But
         with self.assertRaisesRegex(ValueError, "DatasetRef given, cannot use dataId as well"):
             butler.get(ref, dataId)
         # Getting with an explicit ref should fail if the id doesn't match.
-        with self.assertRaises(FileNotFoundError):
+        with self.assertRaises((FileNotFoundError, DatasetNotFoundError)):
             butler.get(DatasetRef(ref.datasetType, ref.dataId, id=uuid.UUID(int=101), run=butler.run))
 
         # Getting a dataset with unknown parameters should fail

tests/test_server.py

@@ -48,6 +48,7 @@
 from lsst.daf.butler import (
     Butler,
     DataCoordinate,
+    DatasetNotFoundError,
     DatasetRef,
     LabeledButlerFactory,
     MissingDatasetTypeError,
@@ -229,7 +230,7 @@ def test_get(self):
         self.assertEqual(metric, kwarg_data_coordinate_metric)
         # Test get() of a non-existent DataId.
         invalid_data_id = {"instrument": "NotAValidlInstrument", "visit": 423}
-        with self.assertRaises(FileNotFoundError):
+        with self.assertRaises(DatasetNotFoundError):
             self.butler_without_error_propagation.get(
                 dataset_type, dataId=invalid_data_id, collections=collections
             )
@@ -245,7 +246,7 @@ def test_get(self):
 
         # Test looking up a non-existent ref
         invalid_ref = ref.replace(id=uuid.uuid4())
-        with self.assertRaises(FileNotFoundError):
+        with self.assertRaises(DatasetNotFoundError):
             self.butler_without_error_propagation.get(invalid_ref)
 
         with self.assertRaises(RuntimeError):