GitHub - SlimIO/Immutable: Group of useful functions that allow to create and manage Immutable and sealed properties and objects.

Group of useful functions that allow to create and manage Immutable and sealed properties and objects.

⚠️ Experimental Project (Please do not use in production)

Requirements

Node.js v12 or higher

Getting Started

This package is available in the Node Package Repository and can be easily installed with npm or yarn.

$ npm i @slimio/immutable
# or
$ yarn add @slimio/immutable

Usage example

const { freezedProperty, seal } = require("@slimio/immutable");

class User {
    constructor(name, age) {
        // Produce readyonly properties
        freezedProperty(this, "name", name);
        freezedProperty(this, "age", age);
    }
}
User.properties = seal({
    name: "param as a string"
});
Object.preventExtensions(User);

const obj = new User("fraxken", 16);
console.log(obj.name);
console.log(obj.age);

API

seal< T extends object >(target: T): T

Same as Object.seal() but doesn't allow to cast the original property type:

const obj = Immutable.seal({
    foo: "bar"
});
obj.foo = "world"; // ok
obj.foo = 10; // Error: Unable to cast string to number for propertyKey foo

freezedProperty(target: object, propertyKey: symbol | string, value?: any): void

Setup a freezed property on a given target (Same behavior as Object.freeze but for all kind of values).

const obj = {};
Immutable.freezedProperty(obj, "foo", "bar");
console.log(obj.foo); // stdout bar
delete obj.foo; // Error

Dependencies

Name	Refactoring	Security Risk	Usage
@slimio/is	Minor	Low	Type checker

License

MIT