Getting started with tSQLt is really easy- you download a zip file, unzip the contents and then run the tSQLt.class.sql script against your development database.
There are a couple of requirements, including CLR integration must be enabled and your database must be set to trustworthy. These could open up some security considerations, but for my development environment it’s no issue.
This is where I’d say putting the database in a container would be extremely helpful, as then you can destroy it afterward. I’m not sure if that’d work, as SQL Server on Linux doesn’t support unsafe or external access assemblies (and I’m not sure what tSQLt requires there).