Make sure fs exceptions are raised if not Missing

zarr/storage.py

@@ -1417,9 +1417,14 @@ def getitems(
     ) -> Mapping[str, Any]:
 
         keys_transformed = [self._normalize_key(key) for key in keys]
-        results = self.map.getitems(keys_transformed, on_error="omit")
+        results = self.map.getitems(keys_transformed, on_error="return")
         # The function calling this method may not recognize the transformed keys
         # So we send the values returned by self.map.getitems back into the original key space.
+        for k, v in results.copy().items():
+            if isinstance(v, self.exceptions):
+                results.pop(k)
+            elif isinstance(v, Exception):
+                raise v
         return {keys[keys_transformed.index(rk)]: rv for rk, rv in results.items()}
 
     def __getitem__(self, key):

zarr/tests/test_storage.py

@@ -1341,6 +1341,22 @@ def test_s3_complex(self):
         )
         assert (a[:] == -np.ones((8, 8, 8))).all()
 
+    def test_exceptions(self):
+        import fsspec
+        m = fsspec.filesystem("memory")
+        g = zarr.open_group("memory://test/out.zarr", mode='w')
+        arr = g.create_dataset("data", data=[1, 2, 3, 4],
+                               dtype="i4", compression=None, chunks=[2])
+        m.store["/test/out.zarr/data/0"] = None
+        del m.store["/test/out.zarr/data/1"]
+        assert g.store.getitems(["data/1"]) == {}  # not found
+        with pytest.raises(Exception):
+            # None is bad data, as opposed to missing
+            g.store.getitems(["data/0", "data/1"])
+        with pytest.raises(Exception):
+            # None is bad data, as opposed to missing
+            arr[:]
+
 
 @pytest.mark.skipif(have_fsspec is False, reason="needs fsspec")
 class TestFSStoreWithKeySeparator(StoreTests):