Q: If I’m writing an Ante Test and I want to call a function from another contract with a non-standard interface (i.e. not an ERC20 token, etc), what is the best way to do so?
A: If the project has an npm package you can import directly from there via
@project/path/to/contract; otherwise, you can copy the interface file into your repo and import or even just paste it in the source code of your Ante Test if you don't think it'll be used elsewhere. If desired, you can define a minimal interface for just the functions you need, but in practice, people prefer importing the entire interface.