Allow appending empty paths

Author: forman

tests/fsutil/test_fileobj.py

@@ -85,6 +85,12 @@ def test_close(self):
 
     def test_truediv_override(self):
         root = FileObj("s3://eo-data/test.zarr")
+
+        derived = root / ""
+        self.assert_derived_ok(root, derived,
+                               "s3://eo-data/test.zarr",
+                               "eo-data/test.zarr")
+
         derived = root / ".zgroup"
         self.assert_derived_ok(root, derived,
                                "s3://eo-data/test.zarr/.zgroup",
@@ -153,6 +159,12 @@ def test_parent_with_chained_uri(self):
 
     def test_for_path(self):
         root = FileObj("s3://eo-data/test.zarr")
+
+        derived = root.for_path("")
+        self.assert_derived_ok(root, derived,
+                               "s3://eo-data/test.zarr",
+                               "eo-data/test.zarr")
+
         derived = root.for_path(".zgroup")
         self.assert_derived_ok(root, derived,
                                "s3://eo-data/test.zarr/.zgroup",

zappend/fsutil/fileobj.py

@@ -125,6 +125,9 @@ def for_path(self, rel_path: str) -> "FileObj":
         if rel_path.startswith("/"):
             raise ValueError("rel_path must be relative")
 
+        if not rel_path:
+            return self
+
         if "::" in self.uri:
             # If uri is a chained URL, add path to first component
             first_uri, rest = self.uri.split("::", maxsplit=1)

zappend/processor.py

@@ -96,7 +96,7 @@ def create_target_from_slice(ctx: Context,
                           consolidated=True)
     finally:
         if target_dir.exists():
-            rollback_cb("delete_dir", target_dir.path, None)
+            rollback_cb("delete_dir", "", None)
 
 
 def update_target_from_slice(ctx: Context,