Test.Tasty.LeanCheck

LeanCheck support for the Tasty test framework.

Here's how your test.hs might look like:

import Test.Tasty
import Test.Tasty.LeanCheck as LC
import Data.List

main :: IO ()
main = defaultMain tests

tests :: TestTree
tests = testGroup "Test properties checked by LeanCheck"
  [ LC.testProperty "sort == sort . reverse" $
      \list -> sort (list :: [Int]) == sort (reverse list)
  , LC.testProperty "Fermat's little theorem" $
      \x -> ((x :: Integer)^7 - x) `mod` 7 == 0
  -- the following property do not hold
  , LC.testProperty "Fermat's last theorem" $
      \x y z n ->
        (n :: Integer) >= 3 LC.==> x^n + y^n /= (z^n :: Integer)
  ]

The output for the above program is:

$ ./test
Test properties checked by LeanCheck
  sort == sort . reverse:  OK
    +++ OK, passed 200 tests.
  Fermat's little theorem: OK
    +++ OK, passed 200 tests.
  Fermat's last theorem:   FAIL
    *** Failed! Falsifiable (after 71 tests):
    0 0 0 3

1 out of 3 tests failed (0.00s)

Use --leancheck-tests to configure the maximum number of tests for each property.

Please see the documentation of Test.LeanCheck and Tasty for more details.

Documentation

testProperty :: Testable a => TestName -> a -> TestTree

Create a Test for a LeanCheck Testable property. Example:

LC.testProperty "sort is idempotent" $ \xs -> sort (sort xs :: [Int]) == sort xs

newtype LeanCheckTests

Number of test cases for LeanCheck to generate.

Constructors

LeanCheckTests Int

Instances

Eq LeanCheckTests

Defined in Test.Tasty.LeanCheck

Methods

(==) :: LeanCheckTests -> LeanCheckTests -> Bool

(/=) :: LeanCheckTests -> LeanCheckTests -> Bool

Ord LeanCheckTests

Defined in Test.Tasty.LeanCheck

Methods

compare :: LeanCheckTests -> LeanCheckTests -> Ordering

(<) :: LeanCheckTests -> LeanCheckTests -> Bool

(<=) :: LeanCheckTests -> LeanCheckTests -> Bool

(>) :: LeanCheckTests -> LeanCheckTests -> Bool

(>=) :: LeanCheckTests -> LeanCheckTests -> Bool

max :: LeanCheckTests -> LeanCheckTests -> LeanCheckTests

min :: LeanCheckTests -> LeanCheckTests -> LeanCheckTests

Show LeanCheckTests

Defined in Test.Tasty.LeanCheck

Methods

showsPrec :: Int -> LeanCheckTests -> ShowS

show :: LeanCheckTests -> String

showList :: [LeanCheckTests] -> ShowS

IsOption LeanCheckTests

Defined in Test.Tasty.LeanCheck

Methods

defaultValue :: LeanCheckTests

parseValue :: String -> Maybe LeanCheckTests

optionName :: Tagged LeanCheckTests String

optionHelp :: Tagged LeanCheckTests String

showDefaultValue :: LeanCheckTests -> Maybe String

optionCLParser :: Parser LeanCheckTests

module Test.LeanCheck