I have the following code I am using for creating a challenge on the following site : codewars
describe "Random cases" $ do
it "It should handle random test cases" $
property $ prop_check where
prop_check (Positive x) = solution x == ref_sol x
--- ref_sol function
I would like to set the value of x
in prop_check to be a positive int greater than 4 and at max a five-digit number (no more than five digits, i.e : max value = 99999).
How would I go about approaching it ?
You can use QuickCheck's choose
function to select a value in an inclusive range. The easiest approach is probably to write prop_check
with do
notation:
prop_check :: Gen Bool
prop_check = do
x <- choose (5, 99999) :: Gen Integer
return $ solution x == ref_sol x
Here, x
is an Integer
value between 5
and 99999
.
Depending on the types of solution
and ref_sol
, you may not need the Gen Integer
type annotation on the first line. Since I didn't know the types of those functions, though, I had to add the annotation.