Do not list empty directories and directories with only ignored files/subdirectories in unmanaged output

[xduugu]

Is your feature request related to a problem? Please describe.

chezmoi unmanaged inlcudes empty directories and directories with only ignored files or subdirectories in its output. This makes it harder to tell if there are files left that should be added to chezmoi.

For example, the directory ~/.config/dconf usually only contains a single file, user, but if I add an ignore entry to chezmoiignore

.config/dconf/user

chezmoi unmanaged still lists .config/dconf as unmanaged.

Describe the solution you'd like

chezmoi unmanaged should not include these "empty" directories in its output.

Describe alternatives you've considered

It is possible to ignore the whole directory, for example,

.config/dconf

but in this case, I would not notice if dconf adds another file to its directory that I might want to add to chezmoi.

[halostatue]

I think that this would be worthwhile, but it will take some time to consider how to approach the solution.

Chezmoi uses twpayne/go-vfs, which is modelled after Go's own path.fs.Walk, which processes each directory entry in turn, and if the entry is itself a directory entry, processes the children of the directory. The processing is a closure passed to the Walk function. There is only an error value returned from child records.

This approach is very simple to implement, but means that:

• .config/dconf is printed during the unmanaged function before it knows anything about the contents of .config/dconf.
• There is no error response which indicates "directory is empty".

The former could be fixed by visiting the children of directories first, but the second prevents that from being useful — and it has the unintuitive result of making the output look like:

.config/git/unmanaged
.config/git

instead of the somewhat more intuitive

.config/git
.config/git/unmanaged

Because chezmoi keeps state about what it does know about, there is probably something that could be done, but it's not clear to me exactly what could be done (I'm not that familiar with how those parts of chezmoi interact…yet).