Writing unit tests for singletons...

I would just want to refactor it so it’d be easier to unit test, but need to write unit tests in order to be allowed to refactor. Geez...

You mean by management? I don't believe you'll be allowed to refactor ever

Singletons are Evil(TM). They literally weld your code to a specific implementation and not some promise of a service (e.g. Dependency Injection) if you're doing OO based stuff. Suggestion #1 - if this thing that's using the Singleton is only built/used in a handful of locations, put an interface on the nasty Singleton, DI it via constructor injection & go about your merry way refactoring (that's what I've done in the past).

@alexbrooklyn nah, just management doesn’t really care as long as things work. It’s more about a refactor PR not even going to be looked at unless unit tests can prove that there are no breaking changes