moy-fp/test/Function/empty.test.js

A functional programming library.

import __ from '../../src/Function/__'
/**
 * a -> a | undefined
 */
import empty from '../../src/Function/empty'

test('empty(not using __), String', () => {
  expect(
    empty('murakami')
  ).toBe('')
})

test('empty(not using __), Array', () => {
  expect(
    empty([1, 2, 3, 4])
  ).toEqual([])
})

test('empty(not using __), Object', () => {
  expect(
    empty({
      a: 1,
      b: 2,
      c: 3.
    })
  ).toEqual({})
})

test('empty(not using __), Number', () => {
  expect(
    empty(12)
  ).toEqual(undefined)
})


test('empty(not using __), empty method', () => {
  expect(
    empty({
      empty(){
        return 3
      },
      a: 1,
    })
  ).toEqual(3)
})

test('empty(using __)', () => {
  expect(
    empty(__)('murakami')
  ).toBe('')
})