https://github.com/zarr-developers/zarr/blob/3c8e9291e96e090e20caf6950da69a3cc180652f/zarr/storage.py#L864-L871

This code does not account for subfolders created by this example:

store = zarr.TempStore(dir='/tmpfs')
for name, values in data.items():
    zarr.array(values, store=store, path=name, compressor=compressor, filters=filter)
total_size = store.getsize()

total_size is 26, (24+2 for .zattrs and .zgroup), which is wrong. Subfolders are not accounted for.

My TempStore has the following structure:

.zattrs
.group
name1/
  1
  2
  3
name2/
  1
  2
  3

The file sizes of name1 and name2 are unaccounted for.

Tested with Zarr 2.2.0.