content: -- Copyright 2021 Google LLC
  --
  -- Licensed under the Apache License, Version 2.0 (the "License");
  -- you may not use this file except in compliance with the License.
  -- You may obtain a copy of the License at
  --
  --     https://www.apache.org/licenses/LICENSE-2.0
  --
  -- Unless required by applicable law or agreed to in writing, software
  -- distributed under the License is distributed on an "AS IS" BASIS,
  -- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  -- See the License for the specific language governing permissions and
  -- limitations under the License.
  
  {-# LANGUAGE CPP #-}
  
  module Main where
  
  #ifdef SOLUTION
  import qualified Solution as C
  #else
  import qualified Codelab  as C
  #endif
  
  import Internal (check, test, Tests)
  
  main :: IO ()
  main = check tests
  
  tests :: Tests
  tests =
    [ test "safeHead  []"           Nothing  $ C.safeHead ([] :: [Int])
    , test "safeHead  [8,0,6]"      (Just 8) $ C.safeHead [8,0,6]
    , test "isNothing (Just 42)"    False    $ C.isNothing (Just 42)
    , test "isNothing Nothing"      True     $ C.isNothing Nothing
    , test "fromMaybe 0 (Just 40)"  40       $ C.fromMaybe 0 (Just 40)
    , test "fromMaybe 0 Nothing"    0        $ C.fromMaybe 0 Nothing
    , test "maybe 0 (+2) (Just 40)" 42       $ C.maybe 0 (+2) (Just 40)
    , test "maybe 0 (+2) Nothing"   0        $ C.maybe 0 (+2) Nothing
    ]
  