Stolen from Wikipedia: "FRP is a paradigm using the building blocks of functional programming." I doubt OP was referring to FRP.
In any case: in a functional programming language, you'd just unit test the building blocks (functions). Assuming every function is pure and total, these unit tests should be succinct and mirror your business logic quite closely.
In any case: in a functional programming language, you'd just unit test the building blocks (functions). Assuming every function is pure and total, these unit tests should be succinct and mirror your business logic quite closely.