@pacote/iff/test/index.spec.ts

Conditional expressions with Option support.

import { None, Some } from '@pacote/option'
import { describe, expect, test } from 'vitest'
import { iff } from '../src/index'

describe('when both consequent and alternative functions are provided', () => {
  test('calls consequent when predicate is satisfied', () => {
    const actual = iff(
      true,
      () => 'consequent',
      () => 'alternative',
    )
    expect(actual).toBe('consequent')
  })

  test('calls alternative when predicate fails', () => {
    const actual = iff(
      false,
      () => 'consequent',
      () => 'alternative',
    )
    expect(actual).toBe('alternative')
  })
})

describe('when only the consequent function is provided', () => {
  test('calls consequent when predicate is satisfied, yielding Some(type)', () => {
    const actual = iff(true, () => 'consequent')
    expect(actual).toEqual(Some('consequent'))
  })

  test('yields None when predicate fails and alternative is undefined', () => {
    const actual = iff(false, () => 'consequent')
    expect(actual).toEqual(None)
  })
})