moy-fp/test/Functor/extract.test.js

A functional programming library.

import __ from '../../src/Function/__'
/**
 * Functor f => f a -> a
 * [a] -> [a]
 */
import extract from '../../src/Functor/extract'
import Identity from '../../src/Functor/Identity/index'
import Maybe from '../../src/Functor/Maybe/index'
import IO from '../../src/Functor/IO/index'
import Task from '../../src/Functor/Task/index'

test('extract(not using __), Identity', () => {
  expect(
    extract(Identity.of(12))
  ).toBe(12)
})

test('extract(not using __), Maybe(null)', () => {
  expect(
    extract(Maybe.of(undefined))
  ).toBeNull()
})

test('extract(not using __), Maybe(12)', () => {
  expect(
    extract(Maybe.of(12))
  ).toBe(12)
})

test('extract(not using __), IO', () => {
  expect(
    extract(IO.of(12))
  ).toEqual(expect.any(Function))
})

test('extract(not using __), task', () => {
  expect(
    extract(Task.of(12))
  ).toEqual(expect.any(Function))
})

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

test('extract(not using __), number', () => {
  expect(
    extract(12)
  ).toBeUndefined()
})

test('extract(using __), Identity', () => {
  expect(
    extract(__)(Identity.of(12))
  ).toBe(12)
})