json-diff-patch-v2

JsonDiffPatch

JsonDiffPatch is a library that allows for the diffing and patching of JSON objects.

npm install json-diff-patch-v2
  1. Import JsonDiffPatch in your project:
import { DiffPatcher } from 'json-diff-patch-v2';
  1. Create a DiffPatcher instance:
const diffPatcher = new DiffPatcher();
  1. Use the diff, patch, and reverse methods to work with your JSON objects:
  • Diff: To find the difference between two objects.
  • Patch: To apply a patch to an object.
  • Reverse: To reverse a patch.
const left = { name: 'John', age: 25 };
const right = { name: 'John', age: 26 };

const delta = diffPatcher.diff(left, right);
console.log(delta);
// Output: { age: [25, 26] }
const original = { name: 'John', age: 25 };
const delta = { age: [25, 26] };

const patched = diffPatcher.patch(original, delta);
console.log(patched);
// Output: { name: 'John', age: 26 }

In scenarios where you want to ignore certain properties during diffing, you can use the propertyFilter option.

const options = {
propertyFilter: function(name) {
return name.slice(0, 1) !== '$';
},
};
const diffPatcherWithFilter = new DiffPatcher(options);

const left = { data: { $volatile: 123, stable: 456 } };
const right = { data: { $volatile: 124, stable: 456 } };

const delta = diffPatcherWithFilter.diff(left, right);
console.log(delta);
// Output: undefined (since the change is in a filtered property)