robinfehr

class ActionTypes {
  static REBALANCE = Symbol("REBALANCE");
  static MESSAGE = Symbol("MESSAGE");
  static FETCH = Symbol("FETCH");

  static {
    const enumMap = new Map();
    for (const [key, value] of Object.entries(this)) {
      enumMap.set(key, value);
    }

robinfehr

#!/usr/bin/env python

import atexit
import optparse
import os
from select import select
import shutil
from socket import (error,
                    socket,
                    AF_INET,

robinfehr

// --------------------------- initial code ----------------------------

// index.js
import { someObject } from './ModuleA';
console.log(someObject.property);

// ModuleA.js
export const someObject = {
  property: 100
}

robinfehr

function constructorFn() {
  this.x = 100;
}
constructorFn.prototype.nonStaticFn = function() {
  return this.x;
}
constructorFn.staticFn = function() {
  // this.x; undefined
  return 200;
}

robinfehr

// No need to use "let" here since we never reassign the arr
const arr = [];
arr.push({ property: 1 });

// -----------------------------------------------

// If we want to clear the array by reassigning:
// 
// because we're reassigning a new arr2 to the variable "arr",
// arr1 isn't assigned anymore and therefore gets flagged 

robinfehr

// Of course this is badly written on purpose
// using a constructor fn but it shows that
// .hasOwnProperty is obsolete when using 
// e.g. Object.keys()
function modes() {
  this.type1 = 1;
  this.type2 = 2;
  this.type3 = 4;
}
modes.prototype.type4 = 2; // This is our problem.

robinfehr

// Example: Not so concise, not reusable
const component = { signals: [-33, -70, -80] };

function highlightComponent() {
  // isHighlighted isn't reusable but also no allocation for an extra function happens (see below)
  let isHighligted = false;
  for (let signal of component.signals) {
  if (signal > -34) {
    isHighligted = true;
    break;

robinfehr

function _extends(subClass, superClass) {
  if (typeof superClass !== "function" && superClass !== null) {
    throw new TypeError(
    "Super expression must either be null or a function, not " +
      typeof superClass
    );
  }

  // Set both __proto__ and prototype
  // ----------------------------------

robinfehr

// The class
class classFn {
  constructor(x,y) {
    this.x = x;
    this.y = y;
  }
  multiply() {
    return this.x * this.y;
  }
}

robinfehr

function constructorFn() {
 this.someProperty = "oops!"
}
 
// We've forgotten the "new"
const instance = constructorFn(); 
instance; //undefined
window.someProperty; // oops!