khanghoang

init.vim and settings.vim go under ~/.config/nvim Follow the installation instructions for https://github.com/junegunn/vim-plug and place plug.vim in ~/.config/nvim/autoload

khanghoang

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

khanghoang

docker run -v /datadir:/data/db --name mongo -d mongo --auth

docker exec -it mongo mongo

> use admin
> db.system.users.find()
> db.createUser({ user: 'admin', pwd: 'admin', roles: [ { role: "root", db: "admin" } ] });

> use some-db
> db.createUser({ user: 'user', pwd: 'user', roles: [ "readWrite" ] });

khanghoang

function mapValues(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    // call fn() and re-assign it to results.
    result[key] = fn(obj[key], key);
    return result;
  }, {});
}

function pick(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {

khanghoang

export class EnumSymbol {
    sym = Symbol.for(name);
    value: number;
    description: string;

    constructor(name: string, {value, description}) {

        if(!Object.is(value, undefined)) this.value  = value;
        if(description) this.description  = description;

khanghoang

OS X Preferences

---

most of these require logout/restart to take effect

# Enable character repeat on keydown
defaults write -g ApplePressAndHoldEnabled -bool false

# Set a shorter Delay until key repeat

khanghoang

# Author: Pieter Noordhuis
# Description: Simple demo to showcase Redis PubSub with EventMachine
#
# Update 7 Oct 2010:
# - This example does *not* appear to work with Chrome >=6.0. Apparently,
#   the WebSocket protocol implementation in the cramp gem does not work
#   well with Chrome's (newer) WebSocket implementation.
#
# Requirements:
# - rubygems: eventmachine, thin, cramp, sinatra, yajl-ruby

khanghoang

@kangax's ES6 quiz, explained

@kangax created a new interesting quiz, this time devoted to ES6 (aka ES2015). I found this quiz very interesting and quite hard (made myself 3 mistakes on first pass).

Here we go with the explanations:

Question 1:

(function(x, f = () => x) {

khanghoang

// Promise.all is good for executing many promises at once
Promise.all([
  promise1,
  promise2
]);

// Promise.resolve is good for wrapping synchronous code
Promise.resolve().then(function () {
  if (somethingIsNotRight()) {
    throw new Error("I will be rejected asynchronously!");

khanghoang

var AWS = require('aws-sdk'),
    fs = require('fs');

// http://docs.aws.amazon.com/AWSJavaScriptSDK/guide/node-configuring.html#Credentials_from_Disk
AWS.config.loadFromPath('./aws-config.json');

// assume you already have the S3 Bucket created, and it is called ierg4210-shopxx-photos
var photoBucket = new AWS.S3({params: {Bucket: 'ierg4210-shopxx-photos'}});

function uploadToS3(file, destFileName, callback) {