A unit-tested fizz-buzz in F#

fizzbuzz.fs

module program

let fizzbuzz n = 
    let (|DivisibleBy|_|) x i = if i%x=0 then Some i else None
    match n with
    | DivisibleBy 3 _ & DivisibleBy 5 _ -> "FizzBuzz"
    | DivisibleBy 3 _ -> "Fizz"
    | DivisibleBy 5 _ -> "Buzz"
    | x -> string x

let rec ``Write FizzBuzz for these numbers:`` = function
    | head :: tail -> printfn "%s" (fizzbuzz head); ``Write FizzBuzz for these numbers:`` tail
    | [] -> printfn ""



``Write FizzBuzz for these numbers:`` [1..100]


(********* Sample unit tests *************)
open FsUnit


[<Scenario("We're playing Fizz-Buzz")>]
type ``Given a game of fizz-buzz`` ()=
    [<Then>] member
        check.``when I play fizz-buzz on a number that is prime, I should get that number as a string`` ()=
            (fizzbuzz 7) --> should equal "7"

    [<Then>] member
        check.``when I play fizz-buzz on a number that is divisible by 5 but not 3, I should get "Buzz"`` ()=
            (fizzbuzz 5) --> should equal "Buzz"

    [<Then>] member
        check.``when I play fizz-buzz on a number that is divisible by 3 but not 5, I should get "Fizz"`` ()=
            (fizzbuzz 3) --> should equal "Fizz"

    [<Then>] member
        check.``when I play fizz-buzz on a number that is divisible by both 3 and 5, I should get "FizzBuzz"`` ()=
            (fizzbuzz 15) --> should equal "FizzBuzz"