module Tests exposing (alwaysFalse, alwaysTrue, containsFive, even, isFirstLetter, odd, tests) import Expect import Strain exposing (discard, keep) import String import Test exposing (..) even : Int -> Bool even number = modBy 2 number == 0 odd : Int -> Bool odd number = modBy 2 number == 1 isFirstLetter : String -> String -> Bool isFirstLetter letter word = String.left 1 word == letter alwaysTrue : a -> Bool alwaysTrue _ = True alwaysFalse : a -> Bool alwaysFalse _ = False containsFive : List Int -> Bool containsFive = List.member 5 tests : Test tests = describe "Strain" [ test "empty keep" <| \() -> Expect.equal [] (keep alwaysTrue []) , skip <| test "keeps everything" <| \() -> Expect.equal [ 1, 3, 5 ] (keep alwaysTrue [ 1, 3, 5 ]) , skip <| test "keeps nothing" <| \() -> Expect.equal [] (keep alwaysFalse [ 1, 2, 3 ]) , skip <| test "keeps first and last" <| \() -> Expect.equal [ 1, 3 ] (keep odd [ 1, 2, 3 ]) , skip <| test "keeps neither first nor last" <| \() -> Expect.equal [ 2 ] (keep even [ 1, 2, 3 ]) , skip <| test "keeps strings" <| \() -> Expect.equal [ "zebra", "zombies", "zealot" ] (keep (isFirstLetter "z") [ "apple", "zebra", "banana", "zombies", "cherimoya", "zealot" ]) , skip <| test "keeps list" <| \() -> Expect.equal [ [ 5, 5, 5 ] , [ 5, 1, 2 ] , [ 1, 5, 2 ] , [ 1, 2, 5 ] ] (keep containsFive [ [ 1, 2, 3 ] , [ 5, 5, 5 ] , [ 5, 1, 2 ] , [ 2, 1, 2 ] , [ 1, 5, 2 ] , [ 2, 2, 1 ] , [ 1, 2, 5 ] ] ) , skip <| test "empty discard" <| \() -> Expect.equal [] (discard alwaysTrue []) , skip <| test "discards everything" <| \() -> Expect.equal [] (discard alwaysTrue [ 1, 3, 5 ]) , skip <| test "discards nothing" <| \() -> Expect.equal [ 1, 3, 5 ] (discard alwaysFalse [ 1, 3, 5 ]) , skip <| test "discards first and last" <| \() -> Expect.equal [ 2 ] (discard odd [ 1, 2, 3 ]) , skip <| test "discards neither first nor last" <| \() -> Expect.equal [ 1, 3 ] (discard even [ 1, 2, 3 ]) , skip <| test "discards strings" <| \() -> Expect.equal [ "apple", "banana", "cherimoya" ] (discard (isFirstLetter "z") [ "apple", "zebra", "banana", "zombies", "cherimoya", "zealot" ]) , skip <| test "discards list" <| \() -> Expect.equal [ [ 1, 2, 3 ] , [ 2, 1, 2 ] , [ 2, 2, 1 ] ] (discard containsFive [ [ 1, 2, 3 ] , [ 5, 5, 5 ] , [ 5, 1, 2 ] , [ 2, 1, 2 ] , [ 1, 5, 2 ] , [ 2, 2, 1 ] , [ 1, 2, 5 ] ] ) ]