I don't see the option to create an Azure function class library template in new projects under Visual Studio Mac. If I created one manually - what files do I need to include and what framework target should I use for the library? .net core or .net standard or something custom?
Alternatively - if I use a CSX script file instead, how would I debug that on a mac?
Azure Functions support for Visual Studio for Mac is available in the alpha channel, so you need to switch to that in order to use this functionality.
The tooling there is similar to what is available for Visual Studio 2015, supporting CSX based projects (as opposed to pre-compiled, class library projects) and giving you a local run/debug experience.