module Main (..) where

import Task
import Console
import ElmTest exposing (..)
import Strain exposing (keep, discard)
import String


even =
  \number -> number % 2 == 0


odd =
  \number -> number % 2 == 1


isFirstLetter =
  \letter -> \word -> (String.left 1 word) == letter


lessThanTen =
  \num -> num < 10


tests : Test
tests =
  suite
    "Strain"
    [ test
        "empty keep"
        (assertEqual [] (keep lessThanTen []))
    , test
        "keep everything"
        (assertEqual [ 1, 2, 3 ] (keep lessThanTen [ 1, 2, 3 ]))
    , test
        "keep first and last"
        (assertEqual [ 1, 3 ] (keep odd [ 1, 2, 3 ]))
    , test
        "keep nothing"
        (assertEqual [] (keep even [ 1, 3, 5, 7 ]))
    , test
        "keep neither first nor last"
        (assertEqual [ 2 ] (keep even [ 1, 2, 3 ]))
    , test
        "keep strings"
        (assertEqual
          [ "zebra", "zombies", "zealot" ]
          (keep (isFirstLetter "z") [ "apple", "zebra", "banana", "zombies", "cherimoya", "zealot" ])
        )
    , test
        "empty discard"
        (assertEqual [] (discard lessThanTen []))
    , test
        "discard everything"
        (assertEqual [] (discard lessThanTen [ 1, 2, 3 ]))
    , test
        "discard first and last"
        (assertEqual [ 2 ] (discard odd [ 1, 2, 3 ]))
    , test
        "discard nothing"
        (assertEqual [ 1, 3, 5, 7 ] (discard even [ 1, 3, 5, 7 ]))
    , test
        "discard neither first nor last"
        (assertEqual [ 1, 3 ] (discard even [ 1, 2, 3 ]))
    , test
        "discard strings"
        (assertEqual [ "apple", "banana", "cherimoya" ] (discard (isFirstLetter "z") [ "apple", "zebra", "banana", "zombies", "cherimoya", "zealot" ]))
    ]


port runner : Signal (Task.Task x ())
port runner =
  Console.run (consoleRunner tests)