Test.QuickCheck.Assertions

Module provides convenient functions to do some assertions in QuickCheck properties with pretty printed reasons. For example you can do something like that:

module Main where

import Test.Hspec
import Test.Hspec.QuickCheck
import Test.QuickCheck.Assertions
import Test.QuickCheck.Property

someProp :: Int -> Int -> Result
someProp a b = (a ?> b)

someOtherProp :: Double -> Double -> Result
someOtherProp a b = (a ?== b)

main = hspec $ describe "failing test" $ do
  prop "must fail" $ someProp
  prop "must fail again" $ someOtherProp

And receive pretty printed fail message when testing:

failing test
  - must fail FAILED [1]
  - must fail again FAILED [2]

1) failing test must fail FAILED
*** Failed! (after 1 test):
>>>>>>>>>>>>>> the value
0
>>>>>>>>>>>>>> should be greater than value
0
0
0


2) failing test must fail again FAILED
*** Failed! (after 2 tests and 4 shrinks):
>>>>>>>>>>>>>> expected
0.0
>>>>>>>>>>>>>> but got
1.0
0.0
1.0

Ok, not very well printed, but better than nothing.

Assertions

binAsrt

Arguments

:: String

The reason of fail

-> Bool

If True then test pass

-> Result

The result with fail reason

(?==) :: (Eq a, Show a) => a -> a -> Result

Left argument should be equal to right

(==?) :: (Eq a, Show a) => a -> a -> Result

Right argument should be equal to left

(/=?) :: (Eq a, Show a) => a -> a -> Result

Right argument should not equal to left

(?/=) :: (Eq a, Show a) => a -> a -> Result

Left argument should not equal to right

(>?) :: (Show a, Ord a) => a -> a -> Result

Right argument is less then left

(<?) :: (Show a, Ord a) => a -> a -> Result

Right argument is greater than left

(?>) :: (Show a, Ord a) => a -> a -> Result

Left argument is greater than right

(?<) :: (Show a, Ord a) => a -> a -> Result

Left argument is less then right

(>=?) :: (Show a, Ord a) => a -> a -> Result

Right argument is less or equal to left

(<=?) :: (Show a, Ord a) => a -> a -> Result

Right argument is greater or equal to left

(?>=) :: (Show a, Ord a) => a -> a -> Result

Left argument is greater or equal to right

(?<=) :: (Show a, Ord a) => a -> a -> Result

Left argument is less or equal to right

(~==?) :: (AEq a, Show a) => a -> a -> Result

Right value is almost equal to left

(?~==) :: (AEq a, Show a) => a -> a -> Result

Left value is almost equal to right

Reexports

data Result :: *

The result of a single test.

Instances

Testable Result

Methods

property :: Result -> Property