Having fun recreating some lodash functionality and polyfills

object-entries-polyfills.js

// Just having fun creating some polyfills.

/**
 * A polyfill for Object.prototype.entries.
 *
 * @returns {[string, any][]} An array of tuples where each tuple is a key/value pair.
 */
Object.prototype.entries = Object.prototype.entries || function() {
  const obj = this;

  return Object.keys(obj).filter(obj.hasOwnProperty).map(key => [key, obj[key]]);
}

/**
 * A polyfill for Object.prototype.fromEntries.
 * 
 * @param {[string, any][]} An array of tuples where each tuple is a key/value pair.
 * 
 * @returns {object} An object built from entries.
 */
Object.prototype.fromEntries = Object.prototype.fromEntries || function (entries) {
  return entries.reduce((prev, [key, value]) => {
    prev[key] = value;

    return prev;
  }, {})
}

omit.js

/**
 * Returns a new object with the omitted properties specified.
 * 
 * @param {object} obj The object to omit properties from
 * @param {string[]} propertiesToOmit The list of properties to omit.
 * 
 * @returns {object} A new object with the omitted properties.
 */
function omit(obj, propertiesToOmit = []) {
  if (obj == null || !propertiesToOmit.length) {
    return obj;
  }

  const filteredEntries = Object.entries(obj).filter(([key, value]) => !propertiesToOmit.includes(key));  

  return Object.fromEntries(filteredEntries);;
}

pick.js

/**
 * Returns a new object with only the specified properties.
 * 
 * @param {object} obj
 * @param {string[]} propertiesToPick
 * 
 * @returns {object} A new object with only the specified properties.
 */
function pick(obj, propertiesToPick = []) {
  if (obj == null || !propertiesToPick.length) {
    return obj;
  }

  const filteredEntries = Object.entries(obj).filter(([key, value]) => propertiesToPick.includes(key));

  return Object.fromEntries(filteredEntries);;
}