yarn add -g prettyjson,prettyprint

#yarn vs npm

yarn npm
yarn npm install
yarn add package npm -i -S package



nvm ls nvm use system




Environment variables are passed into the scripts.

This can be tested via:

  scripts: {
    "env": "env | grep NODE"


yarn run env
NODE_ENV=production yarn run env


  DEBUG=express:* yarn start
  DEBUG=express-start yarn start
  DEBUG=knex:* yarn start
  DEBUG=knex:query yarn start
  DEBUG=knex:tx yarn start



mocha -g 'grep patern for function' file


grunt --tasks .

#Bootstrapping a project

brew install yarn
yarn add --dev babel-cli babel-preset-flow eslint flow-bin pre-commit
yarn run eslint -- --init
yarn run flow init


  • No consistency in one app from another.

#Server Side

  • Run latest ES code

#Client Side

  • Transpile it to a version browsers can use
  • Has to use transpiled server side version