Mutable is a JavaScript library that provides a set of utility functions and types for working with mutable and condition-based object mutations. It offers a flexible and extensible way to apply mutations to objects based on specified conditions, making it easier to manage and modify complex data structures.

You can install Mutable using npm:

npm install @codeperate/mutable

Mutable offers the following features:

The Mutable type allows you to define objects with mutable properties. It can specify conditions and mutations to apply to the object.

type Mutable<T extends object = any, K = any> = {
    [Key in keyof T]: Key extends '$mutate' ? T[Key] : T[Key] extends object ? Mutable<ObjectOnly<T[Key]>, K> | Exclude<T[Key], ObjectOnly<T[Key]>> : T[Key];
} & {
    $mutate?: { cond: Condition; key?: string; mutation: DeepPartial<Mutated<T>> | symbol | ((this: K, obj: T, extra: { conditions: MutableCondition[] }) => any) }[];
};

The DeepPartial type allows you to create a deep partial copy of an object, preserving the object's structure while making selected properties optional.

type DeepPartial<T> = T extends Function
    ? T
    : T extends object
    ? {
          [P in keyof T]?: DeepPartial<T[P]>;
      }
    : T;

The applyMutation function is used to apply mutations to an object based on specified conditions. It supports deep object merging and provides options to control the mutation process.

MutateJS supports conditional mutations, allowing you to define conditions that determine whether a mutation should be applied to an object.

The Condition type allows you to define conditions using logical operators such as $and, $or, and $not. The isMatchCondition function checks if an array of conditions matches a given condition.

Here's a quick example of how to use MutateJS:

import { applyMutation, Condition, isMatchCondition, Mutable, MutableCondition, deleteValue } from 'mutatejs';

// Define your data structure
const data: Mutable<MyData> = {
    name: 'John',
    age: 30,
    $mutate: [
        {
            cond: 'nameEqualsAlice',
            mutation: {
                name: 'Alice',
            },
        },
    ],
};

// Define conditions
const conditions: MutableCondition[] = ['nameEqualsAlice'];

// Apply mutations based on conditions
const mutatedData = applyMutation(conditions, data);

console.log(mutatedData);

In this example, we defined a mutable object data with a condition-based mutation. We then used the applyMutation function to apply mutations based on specified conditions.

Mutable is developed and maintained by Mathew and is hosted on GitHub.

Thank you for using Mutable! We hope it simplifies your object mutation needs and enhances your JavaScript projects. If you have any feedback or suggestions, please let us know.