get-in/test/index.js

get value of nested associative structure given array of keys

const test = require('tape')
const getIn = require('../')

test('non-Array path', function (t) {
  t.throws(() => getIn({ 'a': { 'b': 'c' } }))
  t.throws(() => getIn({ 'a': { 'b': 'c' } }, 'a.b'))
  t.throws(() => getIn({ 'a': { 'b': 'c' } }, { 'a': 'b' }))
  t.end()
})

test('an empty path', function (t) {
  const obj = { a: 1 }
  t.equal(getIn(obj, []), obj)
  t.end()
})

test('a simple path', function (t) {
  t.equal(
    getIn(
      {
        'a': 'b'
      },
      ['a']
    ),
    'b'
  )
  t.end()
})

test('a two-level path', function (t) {
  t.equal(
    getIn(
      {
        'a': {
          'b': 'c'
        }
      },
      ['a', 'b']
    ),
    'c'
  )
  t.end()
})

test('a two-level path into arrays', function (t) {
  t.equal(
    getIn(
      [
        'a',
        [
          'b',
          'c'
        ]
      ],
      [1, 1]
    ),
    'c'
  )
  t.end()
})

test('an unresolved path', function (t) {
  t.equal(
    getIn(
      {
        'a': {
          'b': 'c'
        }
      },
      ['a', 'x']
    ),
    undefined
  )
  t.end()
})

test('a path that resolves to undefined property', function (t) {
  t.equal(
    getIn(
      {
        'a': {
          'b': undefined
        }
      },
      ['a', 'b']
    ),
    undefined
  )
  t.end()
})

test('a path that resolves to null property', function (t) {
  t.equal(
    getIn(
      {
        'a': {
          'b': null
        }
      },
      ['a', 'b']
    ),
    null
  )
  t.end()
})

test.skip('object with custom get function', function (t) {
  function Obj (props) {
    this.props = props
  }
  Obj.prototype.get = function get (key) {
    return this.props[key]
  }

  t.equal(
    getIn(
      new Obj({
        'a': new Obj({
          'b': 'c'
        })
      }),
      ['a', 'b']
    ),
    'c'
  )
  t.end()
})

test('returns undefined when object too shallow', function (t) {
  t.equal(getIn(null, [0, 0]), undefined)
  t.end()
})

test('supports default value for unmatched', function (t) {
  t.equal(getIn(null, [0, 0], 'default'), 'default')
  t.equal(getIn({}, ['missing'], 'default'), 'default')
  t.end()
})