Test if two variables in JavaScript are deep equal

deepEqual.js

const baseTypes = [
    "[object Number]",
    "[object String]",
    "[object Undefined]",
    "[object Boolean]",
    "[object Symbol]",
    "[object Function]"
]
function deepEqual(a, b) {
    const typeOfA = Object.prototype.toString.call(a);
    const typeOfB = Object.prototype.toString.call(b);
    if (typeOfA !== typeOfB) {
        return false;
    }
    if (baseTypes.includes(typeOfA)) {
        return a === b;
    }
    if (typeOfA === "[object Array]") {
        if (a.length !== b.length) {
            return false;
        }
        for (let i = 0; i < a.length; i++) {
            if (!deepEqual(a[i], b[i])) {
                return false
            }
        }
    }
    if (typeOfA === "[object Object]") {
        const keysOfA = Object.keys(a);
        const keysOfB = Object.keys(b);
        if (keysOfA.length !== keysOfB.length) {
            return false;
        }
        for (let i = 0; i < keysOfA.length; i++) {
            let key = keysOfA[i];
            if (!deepEqual(a[key], b[key])) {
                return false
            }
        }
    }
    return true;
}

console.log(deepEqual({a: 1, b: [1, 2]}, {a: 1, b: [1, 2, 3]}))