Support MacOS

[mike4aday]

[psycook]

Hi Mike,

I had a look at this requirement this morning and made some simple changes to UserAgentFlow.swift and Salesforce+Image.swift to use NSApplication and NSImage respectively (using preprocessors macros) and it seems to work nicely. My app now runs on iOS and macOS with minimal changes.

My testing has not been robust though. Happy to share the code with you.

Simon

[mike4aday]

Hi @psycook - I'd love to see the code. Would you post here, or open a pull request if that's easier. Thank you