BowlingKata.kt

import com.redspace.fullbowlingkata.BowlingScorer
import com.redspace.fullbowlingkata.given
import org.junit.Assert.assertEquals
import org.junit.Test

class FullBowlingKataTest1 {

    val spare: (BowlingScorer) -> Unit = {
        it.bowl(5)
        it.bowl(5)
    }

    val strike: (BowlingScorer) -> Unit = {
        it.bowl(10)
    }

    fun bowlMany(n: Int, pins: Int): (BowlingScorer) -> Unit {
        return {
            it: BowlingScorer ->
            for (i in 1..n) {
                it.bowl(pins)
            }
        }
    }

    val allGutterBalls: (BowlingScorer) -> Unit = bowlMany(20, 0)

    val givenBowlingScorer = given { BowlingScorer() }

    val bowl: (Int) -> (BowlingScorer) -> Unit = { bowl -> { scorer -> scorer.bowl(bowl) } }
    val scoreIs: (Int) -> (BowlingScorer) -> Unit = { expected -> { scorer -> assertEquals(expected, scorer.score()) } }
    val noScore: (BowlingScorer) -> Unit = scoreIs(0)

    @Test
    fun `All gutter balls scores zero`() {
        givenBowlingScorer whenever allGutterBalls then noScore
    }

    @Test
    fun `All 1s scores 20`() {
        givenBowlingScorer whenever bowlMany(20, 1) then scoreIs(20)
    }

    @Test
    fun `Next ball after spare scores double`() {
        givenBowlingScorer given spare whenever bowl(3) then scoreIs(10 + 3 * 2)
    }

    @Test
    fun `A strike doubles the next two balls`() {
        givenBowlingScorer given strike given bowl(3) whenever bowl(4) then scoreIs(10 + 3 * 2 + 4 * 2)
    }

    @Test
    fun `Perfect game`() {
        givenBowlingScorer whenever bowlMany(12, 10) then scoreIs(300)
    }