content: {-# OPTIONS_GHC -fno-warn-type-defaults #-}
  {-# LANGUAGE RecordWildCards #-}
  
  import Data.Foldable     (for_)
  import Test.Hspec        (Spec, describe, it, shouldBe)
  import Test.Hspec.Runner (configFastFail, defaultConfig, hspecWith)
  
  import SumOfMultiples (sumOfMultiples)
  
  main :: IO ()
  main = hspecWith defaultConfig {configFastFail = True} specs
  
  specs :: Spec
  specs = describe "sumOfMultiples" $ for_ cases test
    where
      test Case{..} = it description assertion
        where
          description = unwords [show factors, show limit]
          assertion   = expression `shouldBe` fromIntegral expected
          expression  = sumOfMultiples (fromIntegral <$> factors)
                                       (fromIntegral     limit  )
  
  data Case = Case { factors  :: [Integer]
                   , limit    ::  Integer
                   , expected ::  Integer
                   }
  
  cases :: [Case]
  cases = [ Case { factors  = [3, 5]
                 , limit    = 1
                 , expected = 0
                 }
          , Case { factors  = [3, 5]
                 , limit    = 4
                 , expected = 3
                 }
          , Case { factors  = [3]
                 , limit    = 7
                 , expected = 9
                 }
          , Case { factors  = [3, 5]
                 , limit    = 10
                 , expected = 23
                 }
          , Case { factors  = [3, 5]
                 , limit    = 100
                 , expected = 2318
                 }
          , Case { factors  = [3, 5]
                 , limit    = 1000
                 , expected = 233168
                 }
          , Case { factors  = [7, 13, 17]
                 , limit    = 20
                 , expected = 51
                 }
          , Case { factors  = [4, 6]
                 , limit    = 15
                 , expected = 30
                 }
          , Case { factors  = [5, 6, 8]
                 , limit    = 150
                 , expected = 4419
                 }
          , Case { factors  = [5, 25]
                 , limit    = 51
                 , expected = 275
                 }
          , Case { factors  = [43, 47]
                 , limit    = 10000
                 , expected = 2203160
                 }
          , Case { factors  = [1]
                 , limit    = 100
                 , expected = 4950
                 }
          , Case { factors  = []
                 , limit    = 10000
                 , expected = 0
                 }
          ]
  