Non integer blockSize causing byte(s) to be omitted from uploaded blobs.

[willavos]

• Package Name: storage-blob
• Package Version: 12.25.0
• Operating system: any
• nodejs
  • version: ? unknown
• browser
  • name/version: chrome
• typescript
  • version: 5.5.3
• Is the bug related to documentation in
  • README.md
  • source code documentation
  • SDK API docs on https://learn.microsoft.com

Describe the bug
A non-integer blockSize in BlockBlobClient.uploadData causes bytes to be omitted (on chunk boundaries?) in the uploaded file. I suspect this is a rounding error!

To Reproduce
Steps to reproduce the behavior:

1. Create a file with 1637734 bytes long:
   • cat /dev/random | head -c 1637734 > test-file
2. Try and upload 20 chunks, (blockSize = file size / 20 which is 81886.7)
3. Observe a missing byte halfway through: du -ab (gives 1637733 ./test-file-downloaded)

Expected behavior
To not omit the byte.

Screenshots
N/A

Additional context
I appreciate that this is a case of GIGO - but believe there should be a warning (at least) for poorly-conditioned blob block size. Additionally, I find it a bit weird that there's different forms of rounding going on, causing bytes to vanish. I don't think there should ever be bytes missing.

[github-actions]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @xgithubtriage.