modern-diff

Compare two data structures and create patches with some additional info. Apply patches to objects. Reverting patches.

Features:

• Can produce RFC 6902 style patches or compact patches
• Supports immutable-js or native-data structures via adapters
• Fastest lcs algorithm for arrays
• Can revert patches
• Can patch objects
• Extensible via adapters
• Tests
• Flow types

Limitations: can produce only add, replace, remove, test patches.

Diff immutable with rfc codec

// diff-rfc-immutable.js
import Immutable from 'immutable'
import {Diff, Rfc9602Codec, ImmutableAdapter} from 'modern-diff'
ImmutableAdapter.Immutable = Immutable

const diff = Diff({
    adapter: ImmutableAdapter,
    codec: Rfc9602Codec
})

diff(
  Immutable.fromJS({a: 1, b: 2, c: 3}),
  Immutable.fromJS({b: 22, c: 3, d: 4})
)
/*
[
  { op: 'test', path: '/a', value: 1 },
  { op: 'remove', path: '/a'},
  { op: 'test', path: '/b', value: 2 },
  { op: 'replace', path: '/b', value: 22 },
  { op: 'add', path: '/d', value: 4 }
]
*/

Diff native with compact codec

import Immutable from 'immutable'
import {Diff, NativeAdapter, CompactCodec} from 'modern-diff'

const diffCompact = Diff({
    adapter: NativeAdapter,
    codec: CompactCodec
})

diffCompact({a: 1, b: 2, c: 3}, {b: 22, c: 3, d: 4})
/*
[
  ['-', ['a'], 1],
  ['r', ['b'], 2, 22],
  ['+', ['d'], 4]
]
*/

Inverting patches

import {Rfc9602Codec, CompactCodec} from 'modern-diff'

CompactCodec.invert([
  ['-', ['a'], 1],
  ['r', ['b'], 2, 22],
  ['+', ['d'], 4]
])
/*
[
  [ '-', [ 'd' ], 4 ],
  [ 'r', [ 'b' ], 22, 2 ],
  [ '+', [ 'a' ], 1 ]
]
*/

Rfc9602Codec.invert([
  { op: 'test', path: '/a', value: 1 },
  { op: 'remove', path: '/a'},
  { op: 'test', path: '/b', value: 2 },
  { op: 'replace', path: '/b', value: 22 },
  { op: 'add', path: '/d', value: 4 }
])

/*
[
  { op: 'test', path: '/d', value: 4 },
  { op: 'remove', path: '/d' },
  { op: 'test', path: '/b', value: 22 },
  { op: 'replace', path: '/b', value: 2 },
  { op: 'add', path: '/a', value: 1 }
]
*/

Patch immutable with rfc codec

import Immutable from 'immutable'
import {Patch, Rfc9602Codec, ImmutableAdapter} from 'modern-diff'
ImmutableAdapter.Immutable = Immutable

const patch = Patch({
    adapter: ImmutableAdapter,
    codec: Rfc9602Codec
})

patch(Immutable.fromJS({a: 1, b: 2, c: 3}), [
  { op: 'test', path: '/a', value: 1 },
  { op: 'remove', path: '/a'},
  { op: 'test', path: '/b', value: 2 },
  { op: 'replace', path: '/b', value: 22 },
  { op: 'add', path: '/d', value: 4 }
])
/*
  Map {b: 22, c: 3, d: 4}
*/