deep-freeze

What is deep-freeze?

The deep-freeze npm package is used to recursively freeze objects, making them immutable. This means that once an object is frozen, it cannot be modified, which is useful for ensuring the integrity of data structures in JavaScript applications.

What are deep-freeze's main functionalities?

Deep Freezing Objects

This feature allows you to deeply freeze an object, making it and all nested objects immutable. Any attempts to modify the object or its nested properties will fail silently in non-strict mode or throw an error in strict mode.

const deepFreeze = require('deep-freeze');

const obj = {
  a: 1,
  b: {
    c: 2
  }
};

deepFreeze(obj);

obj.a = 2; // This will not change the value of obj.a
obj.b.c = 3; // This will not change the value of obj.b.c

console.log(obj); // { a: 1, b: { c: 2 } }

Other packages similar to deep-freeze

deep-freeze-strict

The deep-freeze-strict package is similar to deep-freeze but throws an error when attempting to modify a frozen object, even in non-strict mode. This can be useful for debugging and ensuring that immutability is strictly enforced.

immer

The immer package provides a more flexible approach to immutability by allowing you to work with mutable state in a draft state and then producing an immutable state. It is more powerful and versatile compared to deep-freeze, especially for complex state management.

immutable

The immutable package offers a comprehensive set of immutable data structures, such as List, Map, and Set. It provides more functionality and performance optimizations compared to deep-freeze, making it suitable for large-scale applications.

README

deep-freeze

recursively Object.freeze() objects

example

var deepFreeze = require('deep-freeze');

deepFreeze(Buffer);
Buffer.x = 5;
console.log(Buffer.x === undefined);

Buffer.prototype.z = 3;
console.log(Buffer.prototype.z === undefined);

---

$ node example/deep.js
true
true

methods

var deepFreeze = require('deep-freeze')

deepFreeze(obj)

Call Object.freeze(obj) recursively on all unfrozen properties of obj that are functions or objects.

license

public domain

Based in part on the code snippet from the MDN wiki page on Object.freeze(), which is released to the public domain.