Unittesting in SML

ut.sml

fun toStr (xs:int list) = List.foldl (fn (i,s) => Int.toString(i) ^ " " ^ s) "" xs;

(* returns true if all test cases were successful, false otherwise *)
fun test name (results:bool list) : bool = 
    let fun checkT (t, (failed, total)) = 
            if t then (failed, total + 1) else ([total+1] @ failed, total + 1)
        val (failed, total) = List.foldl checkT ([], 0) results
    in case (failed, total) of 
           (x::xs, t) => (print ("> Failed " ^ name ^ " [" ^ toStr(failed) ^ "] (total " ^ Int.toString(t) ^")\n") ; false)
        | (nil, t) => (print ("> Success " ^ name ^ " (total " ^ Int.toString(t) ^")\n"); true)
    end
        
(* tests given funtion against list of test cases where each case is tuple (inputparam, result) *)
fun testD name f cases = 
    (test name o List.map (fn (i,r) => (f i = r) handle _ => false)) cases; 

(* usage example *)
fun even i = (i mod 2) = 0;

test "evens" [
    List.all even [1,2,3,4] = false,
    List.all even [2,4] = true,
    List.all even [] = true
];  

(* testing with test case data *)
val filterEvenCases = [
    ([], []),
    ([1,2,3,4], [2,4])
];

testD "testFilterEven" (List.filter even) filterEvenCases;

exception Exn;
test "exception" [
    (fn x => if even x then raise Exn else true) 2 handle Exn => true
]