paths.spec.js

import {paths} from './paths'

const obj = {
  a: {
    b: {
      c: 1,
      d: 2,
    },
  },
  p: [{q: 3}],
  x: {
    y: 'FOO',
    z: [[{}]],
  },
}

test('with string path + curry', () => {
  const pathsInput = ['a.b.d', 'p.q']
  const expected = [2, undefined]
  const result = paths(pathsInput, obj)
  const curriedResult = paths(pathsInput)(obj)

  expect(result).toEqual(expected)
  expect(curriedResult).toEqual(expected)
})

test('with array path', () => {
  const result = paths(
    [
      ['a', 'b', 'c'],
      ['x', 'y'],
    ],
    obj
  )

  expect(result).toEqual([1, 'FOO'])
})

test('takes a paths that contains indices into arrays', () => {
  expect(
    paths(
      [
        ['p', 0, 'q'],
        ['x', 'z', 0, 0],
      ],
      obj
    )
  ).toEqual([3, {}])
  expect(
    paths(
      [
        ['p', 0, 'q'],
        ['x', 'z', 2, 1],
      ],
      obj
    )
  ).toEqual([3, undefined])
})

test("gets a deep property's value from objects", () => {
  expect(paths([['a', 'b']], obj)).toEqual([obj.a.b])
  expect(paths([['p', 0]], obj)).toEqual([obj.p[0]])
})

test('returns undefined for items not found', () => {
  expect(paths([['a', 'x', 'y']], obj)).toEqual([undefined])
  expect(paths([['p', 2]], obj)).toEqual([undefined])
})