Update Array to respect FSStore's key_separator (#718)

* BUG: respect key_separator for FSStore

* TST: add test case for nested FSStore

* TST: switch from zarr.open to open_group

* TST: avoid FSStore test method duplication

* skip FSStore tests unless fsspec is available

Author: grlee77

zarr/core.py

@@ -1950,7 +1950,11 @@ def _process_for_setitem(self, ckey, chunk_selection, value, fields=None):
         return self._encode_chunk(chunk)
 
     def _chunk_key(self, chunk_coords):
-        return self._key_prefix + '.'.join(map(str, chunk_coords))
+        if hasattr(self._store, 'key_separator'):
+            separator = self._store.key_separator
+        else:
+            separator = '.'
+        return self._key_prefix + separator.join(map(str, chunk_coords))
 
     def _decode_chunk(self, cdata, start=None, nitems=None, expected_shape=None):
         # decompress

zarr/tests/test_hierarchy.py

@@ -21,13 +21,13 @@
 from zarr.core import Array
 from zarr.creation import open_array
 from zarr.hierarchy import Group, group, open_group
-from zarr.storage import (ABSStore, DBMStore, DirectoryStore, LMDBStore,
-                          LRUStoreCache, MemoryStore, NestedDirectoryStore,
-                          SQLiteStore, ZipStore, array_meta_key, atexit_rmglob,
-                          atexit_rmtree, group_meta_key, init_array,
-                          init_group)
+from zarr.storage import (ABSStore, DBMStore, DirectoryStore, FSStore,
+                          LMDBStore, LRUStoreCache, MemoryStore,
+                          NestedDirectoryStore, SQLiteStore, ZipStore,
+                          array_meta_key, atexit_rmglob, atexit_rmtree,
+                          group_meta_key, init_array, init_group)
 from zarr.util import InfoReporter
-from zarr.tests.util import skip_test_env_var
+from zarr.tests.util import skip_test_env_var, have_fsspec
 
 
 # noinspection PyStatementEffect
@@ -971,6 +971,39 @@ def create_store():
         return store, None
 
 
+@pytest.mark.skipif(have_fsspec is False, reason="needs fsspec")
+class TestGroupWithFSStore(TestGroup):
+
+    @staticmethod
+    def create_store():
+        path = tempfile.mkdtemp()
+        atexit.register(atexit_rmtree, path)
+        store = FSStore(path)
+        return store, None
+
+    def test_round_trip_nd(self):
+        data = np.arange(1000).reshape(10, 10, 10)
+        name = 'raw'
+
+        store, _ = self.create_store()
+        f = open_group(store, mode='w')
+        f.create_dataset(name, data=data, chunks=(5, 5, 5),
+                         compressor=None)
+        h = open_group(store, mode='r')
+        np.testing.assert_array_equal(h[name][:], data)
+
+
+@pytest.mark.skipif(have_fsspec is False, reason="needs fsspec")
+class TestGroupWithNestedFSStore(TestGroupWithFSStore):
+
+    @staticmethod
+    def create_store():
+        path = tempfile.mkdtemp()
+        atexit.register(atexit_rmtree, path)
+        store = FSStore(path, key_separator='/', auto_mkdir=True)
+        return store, None
+
+
 class TestGroupWithZipStore(TestGroup):
 
     @staticmethod