moy-fp/test/Object/pickBy.test.js

A functional programming library.

import __ from '../../src/Function/__'
/**
 * ((v, k) -> Boolean) -> {k: v} -> {k: v}
 */
import pickBy from '../../src/Object/pickBy'

test('pickBy(not using __)', () => {
  expect(
    pickBy((v, k) => k === v)({a: 'a', b: 1, c: 'c', d: 2})
  ).toEqual({a: 'a', c: 'c'})
})

test('pickBy(using __)', () => {
  expect(
    pickBy(__, {a: 'a', b: 1, c: 'c', d: 2})((v, k) => k === v)
  ).toEqual({a: 'a', c: 'c'})
})