Check equality between two items

is-equal.ts

export const isEqual = (obj1: unknown, obj2: unknown) => {
    type GenericObject = {
        [key: string]: unknown;
    };

    function getType(obj: unknown) {
        return Object.prototype.toString.call(obj).slice(8, -1).toLowerCase();
    }

    function areArraysEqual(arr1: unknown[], arr2: unknown[]) {
        if (arr1.length !== arr2.length) return false;

        for (let i = 0; i < arr1.length; i++) {
            if (!isEqual(arr1[i], arr2[i])) return false;
        }

        return true;
    }

    function areObjectsEqual(obj1: GenericObject, obj2: GenericObject) {
        if (Object.keys(obj1).length !== Object.keys(obj2).length) return false;

        for (let key in obj1) {
            if (Object.prototype.hasOwnProperty.call(obj1, key)) {
                if (!isEqual(obj1[key], obj2[key])) return false;
            }
        }

        return true;
    }

    function areFunctionsEqual(func1: Function, func2: Function) {
        return func1.toString() === func2.toString();
    }

    function arePrimitivesEqual(primitive1: unknown, primitive2: unknown) {
        return primitive1 === primitive2;
    }

    let type = getType(obj1);

    if (type !== getType(obj2)) return false;

    if (type === 'array')
        return areArraysEqual(obj1 as unknown[], obj2 as unknown[]);
    if (type === 'object')
        return areObjectsEqual(obj1 as GenericObject, obj2 as GenericObject);
    if (type === 'function')
        return areFunctionsEqual(obj1 as Function, obj2 as Function);
    return arePrimitivesEqual(obj1, obj2);
};