ohash

What is ohash?

The ohash npm package is a utility library for handling objects and hashes in JavaScript. It provides a variety of functions to manipulate and work with objects, including creating hashes, deep cloning, and merging objects.

What are ohash's main functionalities?

Creating hashes from objects

This feature allows you to create a unique hash string from a JavaScript object. It is useful for identifying objects or storing them in a hash table.

const ohash = require('ohash');
const myObject = { name: 'John', age: 30 };
const hash = ohash.hash(myObject);
console.log(hash);

Deep cloning objects

This feature provides a method to create a deep clone of an object, ensuring that nested objects are also cloned rather than just copying references.

const ohash = require('ohash');
const original = { name: 'John', details: { age: 30, city: 'New York' } };
const cloned = ohash.clone(original);
console.log(cloned);

Merging objects

This feature allows you to merge two or more objects into a single object, combining their properties. If properties overlap, the last object's properties will take precedence.

const ohash = require('ohash');
const object1 = { name: 'John' };
const object2 = { age: 30 };
const mergedObject = ohash.merge(object1, object2);
console.log(mergedObject);

Other packages similar to ohash

lodash

Lodash is a comprehensive utility library that offers similar functionalities to ohash, such as deep cloning and merging objects. Lodash is more extensive and widely used in the industry, providing a broader range of functions and better performance optimizations.

deepmerge

Deepmerge is a package specifically designed for merging objects deeply. While ohash provides this functionality, deepmerge offers more advanced options for controlling the merge process, such as array concatenation and custom merge functions.

README

ohash

Super fast hashing library written in Vanilla JS

Usage

Install package:

# npm
npm install ohash

# yarn
yarn add ohash

# pnpm
pnpm install ohash

Import:

// ESM
import { hash, objectHash, murmurHash, sha256 } from "ohash";

// CommonJS
const { hash, objectHash, murmurHash, sha256 } = require("ohash");

hash(object, options?)

Converts object value into a string hash using objectHash and then applies sha256 with Base64 encoding (trimmed by length of 10).

Usage:

import { hash } from "ohash";

// "dZbtA7f0lK"
console.log(hash({ foo: "bar" }));

objectHash(object, options?)

Converts a nest object value into a stable and safe string for hashing.

Usage:

import { objectHash } from "ohash";

// "object:1:string:3:foo:string:3:bar,"
console.log(objectHash({ foo: "bar" }));

isEqual(obj1, obj2, options?)

Compare two objects using reference equality and stable object hashing.

Usage:

import { isEqual } from "ohash";

// true
console.log(isEqual({ a: 1, b: 2 }, { b: 2, a: 1 }));

diff(obj1, obj2, options?)

Compare two objects with nested hashing. Returns an array of changes.

Returned value is an array of diff entries with $key, $hash, $value and $props. When logging, a string version of changelog is displayed.

Usage:

import { diff } from "ohash";

const createObject = () => ({
  foo: "bar",
  nested: {
    y: 123,
    bar: {
      baz: "123",
    },
  },
});

const obj1 = createObject();
const obj2 = createObject();

obj2.nested.x = 123;
delete obj2.nested.y;
obj2.nested.bar.baz = 123;

const diff = diff(obj1, obj2);

// [-] Removed nested.y
// [~] Changed nested.bar.baz from "123" to 123
// [+] Added   nested.x
console.log(diff(obj1, obj2));

murmurHash(str)

Converts input string (of any length) into a 32-bit positive integer using MurmurHash3.

Usage:

import { murmurHash } from "ohash";

// "427197390"
console.log(murmurHash("Hello World"));

sha256

Create a secure SHA 256 digest from input string.

import { sha256 } from "ohash";

// "a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e"
console.log(sha256("Hello World"));

sha256base64

Create a secure SHA 256 digest in Base64 encoding from input string.

import { sha256base64 } from "ohash";

// "pZGm1Av0IEBKARczz7exkNYsZb8LzaMrV7J32a2fFG4"
console.log(sha256base64("Hello World"));

💻 Development

• Clone this repository
• Enable Corepack using corepack enable (use npm i -g corepack for Node.js < 16.10)
• Install dependencies using pnpm install
• Run interactive tests using pnpm dev

License

Made with 💛

Published under MIT License.

Based on puleos/object-hash by Scott Puleo, and implementations from perezd/node-murmurhash and garycourt/murmurhash-js by Gary Court and Austin Appleby and brix/crypto-js.

Changelog

v1.1.4

compare changes

🩹 Fixes

• murmurHash: Fix murmurHash3 implementation, add tests (#83)

📖 Documentation

• Improved and finalized jsdocs in exported functions (#74)

🏡 Chore

• Update badge (#46)
• Update links in readme (#59)
• Update repo (e09027f)

❤️ Contributors

• Max (@onmax)
• Pooya Parsa (@pi0)
• Hexagon [e-mail]
• Estéban (@Barbapapazes)
• Luke Nelson [e-mail]