How to setup icon based on filename ending pattern?

[ymn64]

I want to setup a different Go icon for files that end with _test.go.
I tried this:

['_test.go'] = { --[[ ... ]] },

And:

['_test.go$'] = { --[[ ... ]] },

Doesn't work.

[gegoune]

Please have a look if override works for your use case (#36 (comment)).