Support zipping empty directories

[kiendang]

Currently empty directories are excluded when zipping.

[lihaoyi]

So my understanding of the expected behavior from the current docs (https://github.com/com-lihaoyi/os-lib#oszip) is that folders directly referenced in the zip call's sourcePaths are unpacked into the root of the zip by default, unless they are given an explicit destination path in the zip via -> os.sub / "renamed-folder"

In that case, ignoring empty directories as shown in your test case os.zip(sources = Seq(emptyDir, outerEmptyDir)) seems like the right thing to do, and this change would make it inconsistent with the behavior for non-empty directories

[kiendang]

I see. Updated the PR to handle zipping empty directories

• specified in sources
  • without dest -> ignored
  • with dest -> included
• inside one of the sources -> included

In cases that empty directories are included in the zip, their names should also follow includePatterns/excludePatterns?

[lihaoyi]

@kiendang good question about the includePatterns/excludePatterns. What does the unix zip command do?

[kiendang]

Yup the zip command on Mac does support -x/-i for empty directories. Updated.