either-spec.ts

import {either} from 'rambda'

describe('R.either', () => {
  it('with passed type', () => {
    const fn = either<number>(
      x => x > 1,
      x => x % 2 === 0
    )
    fn // $ExpectType Predicate<number>
    const result = fn(2) // $ExpectType boolean
    result // $ExpectType boolean
  })
  it('with passed type - curried', () => {
    const fn = either<number>(x => x > 1)(x => x % 2 === 0)
    fn // $ExpectType Predicate<number>
    const result = fn(2)
    result // $ExpectType boolean
  })
  it('no type passed', () => {
    const fn = either(
      x => {
        x // $ExpectType any
        return x > 1
      },
      x => {
        x // $ExpectType any
        return x % 2 === 0
      }
    )
    const result = fn(2)
    result // $ExpectType boolean
  })
  it('no type passed - curried', () => {
    const fn = either((x: number) => {
      x // $ExpectType number
      return x > 1
    })((x: number) => {
      x // $ExpectType number
      return x % 2 === 0
    })
    const result = fn(2)
    result // $ExpectType boolean
  })
})