Add test cases to test rohmu's handling zero size file

[0xlianhu]

Add test cases to test Rohmu handle zero size files:

Generate an empty file -> compress(lzma/zstd/snappy) and encrypt -> upload (local file system) -> download, decrypt+decompress -> Verify if download files are expected files

Moved this test case to Rohmu instead.

Aiven-Open/rohmu#156

[codecov-commenter]

Codecov Report

Merging #603 (b7a4c9a) into main (6fee738) will decrease coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #603      +/-   ##
==========================================
- Coverage   91.30%   91.28%   -0.03%     
==========================================
  Files          32       32              
  Lines        4727     4727              
==========================================
- Hits         4316     4315       -1     
- Misses        411      412       +1     

see 2 files with indirect coverage changes

[Mulugruntz]

Please see the comments in thread.
Also, there are places that also apply but I didn't want to repeat the same comment in several places :).

[0xlianhu]

Please see the comments in thread. Also, there are places that also apply but I didn't want to repeat the same comment in several places :).

Thank you very much for your valuable comments. The file was updated according to your comments.

Comments addressed

[Mulugruntz]

This looks very good, @0xlianhu !

It seems you missed some of the previous comments (had to click on "expand"). I'll let you read them. The PR is good as it is already. Ping me if you want me to merge it as-is. Otherwise, that gives you some time to re-read.

[Mulugruntz]

That's looking great! Less lines = usually a good thing :-).

[packi]

The new test doesn't seem to include anything besides rohmu, so it's probably better suited to be in that code base?

[0xlianhu]

Moving the PR to Rohmu repo instead as @packi suggested.
Aiven-Open/rohmu#156