How to find the list of icons that can be used in mac cli applications

I'm currently developing a node cli application and having used npm tools, my interest has been piqued by the use of npm-check and its use of icons in its cli interface. eg:

There must be plenty of other icons apart from the heart illustrated, but I'd like to know how to access them, so I can use in my own cli applications.

I'm currently using macos, but hopefully these icons are platform independent(?)

The list of icons is static and not likely to change. This is not a request for recommendation, it a request for factual information. There must be a list of icons that the terminal can use. I am trying t find out what this is.

The Terminal available in macOS is capable of displaying the Unicode encoded Emoji that are available on the system.

You can see a great list of these over at Emojipedia. While these are noted as being from iOS, generally Apple keeps the supported version of Unicode in sync between iOS and macOS.

I also found some great information about working with Emoji on macOS on NSHipster written by Mattt.