exercise if two are values are strictly equal without using Equality operators: `==`, `===`, `!=`, `!==`, or `Object.is()`

strictEquals.js

// exercise if two are values are strictly equal
// without using Equality operators: ==, ===, !=, !==
// or Object.is()
const isObject = (val) => {
  if (!val) return false;
  return (typeof val).match(/object|function/);
};

const strictEquals = (a, b) => {
  // a and b are both objects
  if (isObject(a) && isObject(b)) {
    let aLength = Object.keys(a).length;
    let bLength = Object.keys(b).length;

    // amount of keys don't match
    if (aLength - bLength) {
      return false;
    }

    let isEmpty = true;
    let tempKey;
    let tempVal;

    // remove one key in a,
    // which will reflect in b
    // if it points to same object as a
    for (const key in a) {
      tempKey = key;
      tempVal = a[key];
      delete a[key];
      isEmpty = false;
      break;
    }

    // checking if a and b were already empty to begin with
    if (!isEmpty) {
      // check amount of keys for both again
      aLength = Object.keys(a).length;
      bLength = Object.keys(b).length;
      // if amount of keys match, they share the same object
      if (!(aLength - bLength)) {
        a[tempKey] = tempVal;
        return true;
      }
      a[tempKey] = tempVal;
      return false;
    } else {
      // it's safe to add a key since both
      // a and b are empty
      a.prod = true;
      if (b.prod) {
        // restore input object, avoid side effects
        delete a.prod;
        return true;
      }
      // restore input object, avoid side effects
      delete a.prod;
      return false;
    }
  }

  // if a and b are primitives or one of them are objects
  const map = {};
  map[a] = true;
  map[b] = true;
  // keys are converted to strings
  // this is problem where 0 and "0" will both result in "0"
  // storing the type as key as well is an additional measure
  map[typeof a] = true;
  map[typeof b] = true;

  // if a and b are the same, the map will only have two keys
  const result = !(Object.keys(map).length - 2);

  if (result) {
    if (map["NaN"]) return false;
  }

  return result;
};

/***** Tests  ****/

const objA = { docker: "🐋" };
const objB = { docker: "🐋" };
const objC = { key: "🐠", docker: "🐋" };
const objD = {};
const arrA = ["🌊", "👋"];
const arrB = ["🌊", "👋"];
const arrC = ["🌊", "👋", "wut"];
const arrD = [];
const funcA = () => {
  return 42;
};
const funcB = () => {
  return 42;
};

console.log(NaN === NaN, strictEquals(NaN, NaN));
console.log(NaN === 4, strictEquals(NaN, 4));
console.log(0 === -0, strictEquals(0, -0));
console.log(0 === "0", strictEquals(0, "0"));
console.log(3 === 3, strictEquals(3, 3));
console.log("0" === "-0", strictEquals("0", "-0"));
console.log(-0 === +0, strictEquals(-0, +0));
console.log(0 === 0, strictEquals(0, 0));
console.log("" === 0, strictEquals("", 0));
console.log("" === 1, strictEquals("", 1));
console.log("" === "", strictEquals("", ""));
console.log(1 === 1, strictEquals(1, 1));
console.log(1 === -1, strictEquals(1, -1));
console.log(undefined === null, strictEquals(undefined, null));
console.log(null === null, strictEquals(null, null));
console.log(Infinity === Infinity, strictEquals(Infinity, Infinity));
console.log(Infinity === -Infinity, strictEquals(Infinity, -Infinity));
console.log("hi" === "hi", strictEquals("hi", "hi"));
console.log("hi" === "bye", strictEquals("hi", "bye"));
console.log(true === true, strictEquals(true, true));
console.log(true === false, strictEquals(true, false));
console.log(false === false, strictEquals(false, false));
console.log(funcA === funcA, strictEquals(funcA, funcA));
console.log(funcA === funcB, strictEquals(funcA, funcB));
console.log(objA === objA, strictEquals(objA, objA));
console.log(objA === objB, strictEquals(objA, objB));
console.log(objA === objC, strictEquals(objA, objC));
console.log(objD === objD, strictEquals(objD, objD));
console.log({} === {}, strictEquals({}, {}));
console.log(arrA === arrA, strictEquals(arrA, arrA));
console.log(arrA === arrB, strictEquals(arrA, arrB));
console.log(arrA === arrC, strictEquals(arrA, arrC));
console.log(arrD === arrD, strictEquals(arrD, arrD));
console.log([] === [], strictEquals([], []));
console.log({} === [], strictEquals({}, []));