A test comparison between Hunit and Hspec.

tasty_hunit_hspec.hs

module Main where

import Test.Tasty
import Test.Tasty.HUnit
import Test.Tasty.Hspec

main :: IO ()
main = do 
    hspec01    <- spec01           -- spec01 :: IO TestTree  -> IO monad
    let hunit01 = test01           -- test01                 -> pure
    defaultMain $ testGroup "A test comparison between Hunit and Hspec." [hunit01, hspec01] 

-- HUnit Bridge
test01 :: TestTree
test01 = testCase "my_hunit_01" $  -- testCase    :: TestName -> Assertion -> TestTree
  assertEqual "1+2=2 ?" myTest 2   -- assertEqual :: (Show a, Eq a) => String -> a -> a -> Assertion

-- HSpec Bridge
spec01 :: IO TestTree
spec01 = testSpec "my_hspec_01" $  -- testSpec    :: TestName -> Spec -> IO TestTree
  it "1+2=2 ?" $                   -- it          :: (HasCallStack, Example a) => String -> a -> SpecWith (Arg a) 
    myTest `shouldBe` 2            -- shouldBe    :: (Show a, Eq a) => a -> a -> Expectation

myTest :: Int
myTest = 1 + 2

{-

assertXXXX = it + shouldXXXX

> :t assert
assert              assertBool          assertEqual         assertFailure       assertString        assertionPredicate

> :t should
shouldBe          shouldEndWith     shouldNotBe       shouldNotReturn   shouldReturn      shouldStartWith
shouldContain     shouldMatchList   shouldNotContain  shouldNotSatisfy  shouldSatisfy     shouldThrow

-}

-- >>> :l test/MyTest03.hs
-- [1 of 1] Compiling Main             ( test/MyTest03.hs, interpreted )
-- Ok, modules loaded: Main.
-- >>> main
-- A test comparison between Hunit and Hspec.
--   my_hunit_01: FAIL
--     1+2=2 ?
--     expected: 3
--      but got: 2
--   my_hspec_01
--     1+2=2 ?:   FAIL
--       expected 2, but got 3
-- 
-- 2 out of 2 tests failed (0.00s)
-- *** Exception: ExitFailure 1