epsitec-immutablediff

Immutable Diff

Create RFC 6902 style patches between Immutable.JS data structures, such as Maps, Lists, and Sets.

Differences from original

Signature of diff function is

function diff(a, b, p, s)

where if s = true, then sequence diffs are ignored and a single block is generated.
This can be usefull as an optimization. If s is a string (identification key of all elements), an additional optimization will be performed, detecting if all elements of a list have changed (in this case a complete change), or just some elements (in this case a granular diff)

Getting Started

Install immutablediff using npm or yarn:

# npm...
npm install --save immutablediff

# ...or yarn
yarn add immutablediff

You can then use it to get the diff ops between you Immutable.JS data structures.

var Immutable = require('immutable');
var diff = require('immutablediff');

var map1 = Immutable.Map({a:1, b:2, c:3});
var map2 = Immutable.Map({a:1, b:2, c:3, d: 4});

diff(map1, map2);
// List [ Map { op: "add", path: "/d", value: 4 } ]

The result of diff is an Immutable Sequence of operations

Immutable Patch

If you want to use the resulting diff to apply patches to other Immutable data structures, you can use the package immutablepatch. Source code available here