branneman

Better local require() paths for Node.js

Problem

When the directory structure of your Node.js application (not library!) has some depth, you end up with a lot of annoying relative paths in your require calls like:

const Article = require('../../../../app/models/article');

Those suck for maintenance and they're ugly.

Possible solutions

branneman

// Factory
var encrypterFactory = function(config) {
    var encrypter = eval('new Encrypt' + config.algorithm.toUpperCase());
    if (typeof encrypter.encrypt !== 'function') {
        throw new Error(encrypter.constructor.name + ' must implement the `encrypt` method!');
    }
    return encrypter;
};

// Implementations

branneman

<?php
class Struct
{
    /**
     * Define a new struct object, a blueprint object with only empty properties.
     */
    public static function factory()
    {
        $struct = new self;
        foreach (func_get_args() as $value) {

branneman

//
// Tight coupling from A to B  => A needs B to be defined, callable and adhere to an interface
// No coupling from B to A     => B does not need A in any way (pure fn)
//
function a() { b() }
function b() {}
a()

//
// No coupling from A to B         => A and B work independently,

branneman

Primitive Types & Reference Types in JavaScript

An explanation of JavaScript's pass-by-value, which is unlike pass-by-reference from other languages.

Facts

• JavaScript has 2 kinds of variable types: primitive and reference.
• A fixed amount of memory is reserved after creation of every variable.
• When a variable is copied, it's in-memory value is copied.
• Passing a variable to a function via a call also creates a copy of that variable.

Primitive Types

branneman

var fn = function(arg1, arg2) {
    var str = '<p>aap ' + this.noot + ' ' + arg1 + ' ' + arg2 + '</p>';
    document.body.innerHTML += str;
};
var context = {
    'noot': 'noot'
};
var args = ['mies', 'wim'];

// Calls a function with a given 'this' value and arguments provided individually.

branneman

const stat = require('fs').statSync;
const AdmZip = require('adm-zip');

/**
 * Example usage
 */
newArchive(`test-${+new Date}.zip`, [
    'index.js',
    'package.json',
    'node_modules'

branneman

const crypto = require('crypto')
const { promisify } = require('util')
const pbkdf2 = promisify(crypto.pbkdf2)

module.exports = { createHashPasswordFn, isPasswordCorrect }

/**
 * @typedef {Object} HashPassword
 * @property {String} hash
 * @property {String} salt

branneman

// :: (String, String) => String
const spawn = require('child_process').spawnSync;

// :: String => [String]
const getRules = raw => raw
    .split('\n')
    .map(line => line.trim())
    .filter(line => !!line)
    .filter(line => line[0] !== '/' && line[0] !== '✖')
    .map(line => line.match(/[a-z-]+$/)[0]);

branneman

/**
 * Globals
 */
var Carrousel = function(elem) { this.init() };
Carrousel.prototype = { init: function() {} };
new Carrousel();

/**
 * Namespacing
 *  - No globals (only the namespace variable itself is global)