jkantr

const Promise = require('bluebird');
const fetch = require('node-fetch');
const cheerio = require('cheerio');

const getAllUrls = () => {
    return fetch('http://regioni.usyouthsoccer.org')
        .then(res => res.text())
        .then((html) => {
            const $ = cheerio.load(html);
            return $('#associationscarousel').find('> li > a').toArray().map(link => $(link).attr('href'))

jkantr

const cartReducer = (state = {
    cartItems: 0,
    items: products,
    cartContents: [],
}, action) => {
    switch (action.type) {
        case "ADD_TO_CART": {
            const existingItem = state.cartContents.find(item => {
                return item.id === Number(action.payload);
            });

jkantr

import BonusContext from './bonus-context';

class App extends Component {
  static contextType = BonusContext;

  render() {
    return(
    <li className={ this.context ? 'current' : '' }>
      <NavLink
         exact

jkantr

Array.from({ length: 100 }, (v, i) => [[15, 'fizzbuzz'], [5, 'buzz'], [3, 'fizz']].find(x => (i+1) % x[0] === 0) || (i + 1))
  .reduce((a, o) => a += (o[1] || o) + "\n",'')

jkantr

Express patterns

Parametric modules

This pattern takes advantage of lexical scope in javascript, CommonJS modules, and object destructuring. It's a good way to share stateful resources, such as a db connection object, to middleware and detached routers in Express.

Basic setup

/app.js:

const express = require('express')

jkantr

// some helper fns.. maybe in a different file or not
function validateEmail(email){
	return false;
}

export default (db) => {
	// define some route handlers
    function onPostCheckMail (req, res) {
    	if(validateEmail(req.body.email) === true){ //validateEmail is undefined

jkantr

	routeConfig.post('/Dashboard/Index', repos.DashboardRepository.getRangeData(repos), (req, res) => {
		let queries = [], 
			sess = req.userSession,
			filter = req.rangeFilter;

		queries.push(repos.PromotionRepository.getAgencyPromotions(sess.agencyId, 'all'));
		queries.push(repos.DashboardRepository.getIndex(repos, filter, sess));
		queries.push(repos.PolicyRepository.getPolicies(filter, true));

		Promise.all(queries)

jkantr

// app.js
// ...

const models = require('./models/');

const state = {
  models,
  logger,
  errorReporter,
};

jkantr

module.exports = {
    startTimer() {
        return process.hrtime()
    },

    stopTimer(timer) {
        const [s, ns] = process.hrtime(timer)
        return ((s * 1e9) + ns) / 1e6
    }
}

jkantr

/** when wrapping a function with many other functions, the identity of the
    original function quickly gets lost, and it's hard to make sense of it 
    at a glance */
const Timer = inject("someStore")(observer(class Timer extends React.Component {
    /* ... */
}))


/** you can make it less hard to read by separating your component's definition
    and it's functional wrappers **/