Object Helper Library

A collection of utility functions for common object operations in TypeScript.

Installation

To install the package, use:

npm install @jlhv/object-helper

Usage

Import the library and use its functions:

import * as ObjectHelper from "@jlhv/object-helper";

const obj = { a: 1, b: 2, c: 3 };
console.log(ObjectHelper.isEmpty(obj)); // false

API Reference

isEmpty(obj: Record<string, any>): boolean

Checks if an object is empty.

ObjectHelper.isEmpty({}); // true
ObjectHelper.isEmpty({ key: "value" }); // false

merge<T, U>(obj1: T, obj2: U): T & U

Merges two objects without modifying the originals.

const merged = ObjectHelper.merge({ a: 1 }, { b: 2 });
console.log(merged); // { a: 1, b: 2 }

deepClone<T>(obj: T): T

Creates a deep copy of an object.

const original = { a: { b: 2 } };
const copy = ObjectHelper.deepClone(original);
console.log(copy); // { a: { b: 2 } }

pick<T, K extends keyof T>(obj: T, keys: K[]): Pick<T, K>

Picks specific keys from an object.

const obj = { a: 1, b: 2, c: 3 };
console.log(ObjectHelper.pick(obj, ["a", "c"])); // { a: 1, c: 3 }

omit<T, K extends keyof T>(obj: T, keys: K[]): Omit<T, K>

Omits specific keys from an object.

console.log(ObjectHelper.omit({ a: 1, b: 2, c: 3 }, ["b"])); // { a: 1, c: 3 }

isEqual<T>(obj1: T, obj2: T): boolean

Checks if two objects are equal (shallow comparison).

ObjectHelper.isEqual({ a: 1 }, { a: 1 }); // true
ObjectHelper.isEqual({ a: 1 }, { a: 2 }); // false

hasNested(obj: Record<string, any>, path: string): boolean

Checks if an object has a nested property.

const obj = { a: { b: { c: 42 } } };
console.log(ObjectHelper.hasNested(obj, "a.b.c")); // true
console.log(ObjectHelper.hasNested(obj, "a.x.y")); // false

getNested<T>(obj: Record<string, any>, path: string, defaultValue?: T): T | undefined

Safely retrieves a nested property.

console.log(ObjectHelper.getNested({ a: { b: { c: 42 } } }, "a.b.c")); // 42
console.log(ObjectHelper.getNested({ a: { b: { c: 42 } } }, "a.x.y", "default")); // "default"

setNested<T>(obj: Record<string, any>, path: string, value: T): void

Sets a nested property in an object.

const obj = { a: { b: {} } };
ObjectHelper.setNested(obj, "a.b.d", 100);
console.log(obj.a.b.d); // 100

invert<T>(obj: T): Record<string, keyof T>

Swaps keys and values in an object.

console.log(ObjectHelper.invert({ a: 1, b: 2 })); // { "1": "a", "2": "b" }

toPairs<T>(obj: T): [keyof T, T[keyof T]][]

Converts an object to an array of key-value pairs.

console.log(ObjectHelper.toPairs({ a: 1, b: 2 })); // [["a", 1], ["b", 2]]

fromPairs<T>(pairs: [string, T][]): Record<string, T>

Creates an object from key-value pairs.

console.log(ObjectHelper.fromPairs([["a", 1], ["b", 2]])); // { a: 1, b: 2 }

freeze<T>(obj: T): Readonly<T>

Freezes an object to prevent modifications.

const frozen = ObjectHelper.freeze({ a: 1 });
// frozen.a = 2; // Error in strict mode

mapValues<T, U>(obj: T, callback: (value: T[keyof T], key: keyof T) => U): Record<keyof T, U>

Applies a function to each value in an object.

console.log(ObjectHelper.mapValues({ a: 1, b: 2 }, val => val * 2)); // { a: 2, b: 4 }

filter<T>(obj: T, predicate: (value: T[keyof T], key: keyof T) => boolean): Partial<T>

Filters object properties based on a function.

console.log(ObjectHelper.filter({ a: 1, b: 2, c: 3 }, val => val > 1)); // { b: 2, c: 3 }

deepMerge<T, U>(obj1: T, obj2: U): T & U

Performs a deep merge of two objects.

const obj1 = { a: { b: 1 } };
const obj2 = { a: { c: 2 } };
console.log(ObjectHelper.deepMerge(obj1, obj2)); // { a: { b: 1, c: 2 } }

License

ISC License.

Author

Vijayavel R