Where should ruby option parsing be?

I'm wondering where would be the best place to do option parsing in ruby, when creating a gem, with the traditional (bin/, lib/, test/) folder hierarchy.

Specifically, should options be parsed in the executable file in (bi开发者_C百科n/) or in a runner class in lib/? And why?

I've seen it done both ways. Personally, I think much of it depends on your gem; if the option parsing is unique to the binary, put it in the binary, and pass the necessary options to your library. ruby-debug's binary is a good example. However, if your arguments are tied to your classes, such as passing around commands as in Heroku's Command class, feel free to parse the options in your library.