array-changeset

This tiny library can be used to calculate the changeset between two arrays and applying these changes to another array.

The library is ESM-only. See this note by sindresorhus to learn more about that.

Installation

Using npm

npm install array-changeset

Usage

import { Changeset } from 'array-changeset'

const arrayA = ['foo', '!']
const arrayB = ['foo', 'bar']

// Use fromDiff to create a changeset from the difference between two arrays
const changeset = Changeset.fromDiff(arrayA, arrayB)

// Check if there are any changes from arrayA to arrayB
console.log(changeset.hasChanges()) // true

// Access the added and removed elements
console.log(changeset.getAdded()) // ['bar']
console.log(changeset.getRemoved()) // ['!']

// Modify the changeset (arrayA and arrayB are not modified)
changeset.add('!')
changeset.remove('bar')
changeset.remove('more')
changeset.uniquelyAddItem('unique', (a, b) => a === b) // The comparator is optional and defaults to fast-deep-equal
changeset.uniquelyAddItem('unique', (a, b) => a === b)

console.log(changeset.getAdded()) // ['unique']
console.log(changeset.getRemoved()) // ['more']

// Apply the changeset to another array (without modifying arrayC)
const arrayC = ['much', 'more', 'foo', '!']
const modifiedC = changeset.applyOnto(arrayC)
console.log(modifiedC) // ['much', 'foo', '!', 'unique']

// Clear the changeset
changeset.clear()

console.log(changeset.hasChanges()) // false

License

This project is licensed under the MIT License. See the LICENSE file for details.