Self-Hosted WordPress Plugin on GitHub with Automatic Update

I started to try to develop self-hosted WordPress plugin on GitHub with automatic update.

https://github.com/miya0001/gh-auto-updater-example

There are still points to be improved, but it works as expected.

I am developing composer library which enables automatic update with GitHub API.

https://github.com/miya0001/gh-auto-updater

But I have no idea to do PHPUnit for now and I have some issues.