elm/exercises/list-ops/ListOpsTests.elm

module Main exposing (..)

import ElmTest exposing (..)
import ListOps exposing (..)


tests : Test
tests =
    suite "List Ops"
        [ suite "length"
            [ test "empty list" (assertEqual 0 (length []))
            , test "non-empty list" (assertEqual 4 (length [1..4]))
            ]
        , suite "reverse"
            [ test "empty list" (assertEqual [] (reverse []))
            , test "non-empty list" (assertEqual [ 4, 3, 2, 1 ] (reverse [1..4]))
            ]
        , suite "map"
            [ test "empty list" (assertEqual [] (map ((+) 1) []))
            , test "non-empty list" (assertEqual [2..5] (map ((+) 1) [1..4]))
            ]
        , suite "filter"
            [ test "empty list" (assertEqual [] (filter (\_ -> True) []))
            , test "non-empty list"
                (assertEqual [ 2, 4 ] (filter (\x -> x % 2 == 0) [1..4]))
            ]
        , suite "foldl"
            [ test "empty list" (assertEqual 0 (foldl (+) 0 []))
            , test "non-empty list" (assertEqual 10 (foldl (+) 0 [1..4]))
            , test "direction" (assertEqual [4,3,2,1] (foldl (::) [] [1..4]))
            ]
        , suite "foldr"
            [ test "empty list" (assertEqual 0 (foldr (+) 0 []))
            , test "non-empty list" (assertEqual 10 (foldr (+) 0 [1..4]))
            , test "direction" (assertEqual [1..4] (foldr (::) [] [1..4]))
            ]
        , suite "append"
            [ test "empty lists" (assertEqual [] (append [] []))
            , test "empty and non-empty lists"
                (assertEqual [1..4] (append [] [1..4]))
            , test "non-empty and empty lists"
                (assertEqual [1..4] (append [1..4] []))
            , test "non-empty lists" (assertEqual [1..8] (append [1..4] [5..8]))
            ]
        , suite "concat"
            [ test "empty list" (assertEqual [] (concat []))
            , test "list of lists"
                (assertEqual [1..10] (concat [ [1..3], [], [4..7], [8..10] ]))
            ]
        ]


main : Program Never
main =
    runSuite tests