Add explicit test for datastore.export

This required we change the exception type in some failure
modes to match that raise by butler.export.

python/lsst/daf/butler/datastores/chainedDatastore.py

@@ -957,10 +957,10 @@ def export(
     ) -> Iterable[FileDataset]:
         # Docstring inherited from Datastore.export.
         if transfer is not None and directory is None:
-            raise RuntimeError(f"Cannot export using transfer mode {transfer} with no export directory given")
+            raise TypeError(f"Cannot export using transfer mode {transfer} with no export directory given")
 
         if transfer == "move":
-            raise RuntimeError("Can not export by moving files out of datastore.")
+            raise TypeError("Can not export by moving files out of datastore.")
 
         # Exporting from a chain has the potential for a dataset to be
         # in one or more of the datastores in the chain. We only need one

python/lsst/daf/butler/datastores/fileDatastore.py

@@ -2704,10 +2704,10 @@ def export(
     ) -> Iterable[FileDataset]:
         # Docstring inherited from Datastore.export.
         if transfer is not None and directory is None:
-            raise RuntimeError(f"Cannot export using transfer mode {transfer} with no export directory given")
+            raise TypeError(f"Cannot export using transfer mode {transfer} with no export directory given")
 
         if transfer == "move":
-            raise RuntimeError("Can not export by moving files out of datastore.")
+            raise TypeError("Can not export by moving files out of datastore.")
         elif transfer == "direct":
             # For an export, treat this as equivalent to None. We do not
             # want an import to risk using absolute URIs to datasets owned

tests/test_datastore.py

@@ -19,6 +19,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+from __future__ import annotations
+
 import os
 import shutil
 import sys
@@ -33,8 +35,10 @@
 import yaml
 from lsst.daf.butler import (
     Config,
+    DatasetRef,
     DatasetRefURIs,
     DatasetTypeNotSupportedError,
+    Datastore,
     DatastoreCacheManager,
     DatastoreCacheManagerConfig,
     DatastoreConfig,
@@ -817,10 +821,8 @@ def testIngestSymlinkOfSymlink(self):
                     # since it will get the same file name in store
                     datastore.remove(ref)
 
-    def testExportImportRecords(self):
-        """Test for export_records and import_records methods."""
-
-        datastore = self.makeDatastore("test_datastore")
+    def _populate_export_datastore(self, name: str) -> tuple[Datastore, list[DatasetRef]]:
+        datastore = self.makeDatastore(name)
 
         # For now only the FileDatastore can be used for this test.
         # ChainedDatastore that only includes InMemoryDatastores have to be
@@ -837,11 +839,18 @@ def testExportImportRecords(self):
 
         refs = []
         for visit in (2048, 2049, 2050):
-            dataId = {"instrument": "dummy", "visit": visit, "physical_filter": "Uprime"}
+            dataId = FakeDataCoordinate.from_dict(
+                {"instrument": "dummy", "visit": visit, "physical_filter": "Uprime"}
+            )
             ref = self.makeDatasetRef("metric", dimensions, sc, dataId, conform=False)
+            print("REF IS ", repr(ref))
             datastore.put(metrics, ref)
             refs.append(ref)
+        return datastore, refs
 
+    def testExportImportRecords(self):
+        """Test for export_records and import_records methods."""
+        datastore, refs = self._populate_export_datastore("test_datastore")
         for exported_refs in (refs, refs[1:]):
             n_refs = len(exported_refs)
             records = datastore.export_records(exported_refs)
@@ -865,6 +874,18 @@ def testExportImportRecords(self):
         data = datastore2.get(refs[2])
         self.assertIsNotNone(data)
 
+    def testExport(self):
+        datastore, refs = self._populate_export_datastore("test_datastore")
+
+        datasets = list(datastore.export(refs, transfer=None))
+        self.assertEqual(len(datasets), 3)
+
+        with self.assertRaises(TypeError):
+            list(datastore.export(refs))
+
+        with self.assertRaises(TypeError):
+            list(datastore.export(refs, directory="exportDir", transfer="move"))
+
 
 class PosixDatastoreTestCase(DatastoreTests, unittest.TestCase):
     """PosixDatastore specialization"""