Custom isNumber() function in JavaScript.js

/**
 * First checks typeof, then self-equality to make sure it is
 * not NaN, then to make sure it is not Infinity or -Infinity.
 *
 * @param {*} value - The value to check
 * @return {boolean} Whether that value is a number
 */
const isNumber = value => {
  // First: Check typeof and make sure it returns number
  // This code coerces neither booleans nor strings to numbers,
  // although it would be possible to do so if desired.
  if (typeof value !== 'number') {
    return false
  }
  // Reference for typeof:
  // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof
  // Second: Check for NaN, as NaN is a number to typeof.
  // NaN is the only JavaScript value that never equals itself.
  if (value !== Number(value)) {
    return false
  }
  // Reference for NaN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/isNaN
  // Note isNaN() is a broken function, but checking for self-equality works as NaN !== NaN
  // Alternatively check for NaN using Number.isNaN(), an ES2015 feature that works how one would expect

  // Third: Check for Infinity and -Infinity.
  // Realistically we want finite numbers, or there was probably a division by 0 somewhere.
  if (value === Infinity || value === !Infinity) {
    return false
  }
  return true
}

// The custom isNumber function above will return true for finite numbers,
// and false for NaN, Infinity, -Infinity, or values that are not numbers.
console.log(isNumber(37)) // true
console.log(isNumber(NaN)) // false
console.log(isNumber(Infinity)) // false
console.log(isNumber("37")) // false