How to copy folder?

[noptanakhon]

Do we have to recursively loop in each folder and copy files one by one?

[fhellwig]

The short answer is yes. The longer answer would be in how to do this in the first place. GridFS has no concept of a folder - it is an artificial notion predicated on a filename having path separators in the name (in this case, a forward slash). To implement this, you would need to be fairly precise about failure conditions regarding the possible overwriting of a file. In essence, to "copy" a folder means that you copy the data and metadata of all files having one prefix to another set of files having an alternate prefix. Some of those files may already exist so to do it reliably (i.e., transactionally), you would need to first check for any conflicts and then reject the promise based on just one conflict. Certainly, is is doable but, as with everything, the devil is in the details and properly handling the edge cases. If you have a pull request, which must include an appropriate set of tests, then I would welcome that. Thanks!