merge-lite

A lightweight merge utility which the api compatible with lodash _.mergeWith()

1import merge from 'merge-lite'
2merge( object, ...sources, [ customizer ] )

Installation

1npm i merge-lite

Features

• _.mergeWith() api, see docs.
• Support merge a array Array<Object> in the top level by specific property.

Example

1it('shadow merge', () => {
2  var ret = merge(
3    { a: 1, b: 2, c: 3 },
4    { b: 'b' }, { c: '3' }
5  )
6  assert.deepEqual(ret,
7    { a: 1, b: 'b', c: '3' }
8  )
9})
10
11it('nested array', () => {
12  var ret = merge(
13    { f: [ 1, 2, 3 ] },
14    { f: [ 5, 6 ] }
15  )
16  assert.deepEqual(ret,
17    { f: [ 5, 6, 3 ] }
18  )
19})
20
21it('merge by list by indexes', () => {
22  var l1 = [
23    { name: '0', value: '0' },
24    { name: 'a', value: '1' },  // <---
25    { name: 'b', value: '2' },
26  ]
27  var l2 = [
28    { name: 'd', value: 'd', foo: 1 },
29    { name: 'a', value: 'a', foo: 1 },  // <---
30    { name: 'b', value: 'b' },
31    { name: 'c', value: 'c', foo: 1 },
32    { name: 'x', value: 'x', foo: 1 }
33  ]
34
35  /*
36  [ { name: '0', value: '0' },
37    { name: 'a', value: 'a', foo: 1 }, // <<<=-
38    { name: 'b', value: 'b' },
39    { name: 'd', value: 'd', foo: 1 },
40    { name: 'c', value: 'c', foo: 1 },
41    { name: 'x', value: 'x', foo: 1 } ]
42  */
43
44  var ret = merge(l1, l2, () => ({ pk: 'name' }))
45  assert.deepEqual(ret[1],
46    { name: 'a', value: 'a', foo: 1 }
47  )
48})
49
50it('merge by a specific customizer', () => {
51  var objA =
52  {
53    f: [ 1, 2, 3 ],
54    bar: { b: 1, v: false }
55  }
56  var objB =
57  {
58    f: [ 5, 6 ],
59    bar: { b: 'b', a: 'new' }
60  }
61  var ret = merge(objA, objB, (objValue, srcValue, key, targe, source) => {
62    if (Array.isArray(srcValue)) {
63      return objValue.concat(srcValue)
64    }
65  })
66  assert.deepEqual(
67    ret,
68    {
69      f: [1, 2, 3, 5, 6], // <--- concat by customizer
70      bar: { b: 'b', a: 'new', v: false }
71    }
72  )
73})

License

MIT