import { describe, given, it, Test } from '@typed/test'
import { fromJust, isJust, isNothing, Just, Nothing } from './'

import { combineArray } from './combineArray'

export const test: Test = describe(`combineArray`, [
  given(`(a -> b -> c) -> ( Maybe a, Maybe b, Maybe c )`, [
    it(`returns Maybe d`, ({ equal }) => {
      const a = Just.of(1)
      const b = Just.of(2)
      const c = Just.of(3)

      const f = (x: number, y: number, z: number) => x + y + z

      const d = combineArray(f, [a, b, c])

      const expected = 6

      if (isJust(d)) {
        equal(expected, fromJust(d))
      }
    }),
  ]),

  given(`(a -> b -> c) -> Nothing -> Just b`, [
    it(`does not call supplied function and returns Nothing`, ({ ok }) => {
      const a = Nothing
      const b = Just.of(1)

      const f = (x: number, y: number) => x + y

      const c = combineArray(f, [a, b])

      ok(isNothing(c))
    }),
  ]),
])