jsmanifest

function logAndReturnIt(
  valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction: null,
): null {
  console.log(typeof valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction)
  
  return valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction
}

logAndReturnIt(null) // valid
logAndReturnIt(5) // invalid

jsmanifest

const greeting = 'Good morning'
logAndReturnIt(greeting) // logs 'Good morning'
logAndReturnIt('cat') // logs 'cat'

jsmanifest

function logAndReturnIt(
  valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction: string,
): string {
  console.log(typeof valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction)
  
  return valueThatIsGoingToBeLoggedAndReturnedFromAUselessFunction
}

jsmanifest

@filterMales // This is the decorator
class MyClass {
  constructor(children) {
    this.children = children
  }
}

jsmanifest

function Frog(name) {
  this.name = name
}

Frog.prototype.getTeeths = function() {
  return 2
}

Frog.prototype.lick = function(target) {
  console.log(`I'm going lick you, ${target.name}. You better taste delicious`)

jsmanifest

function withToad(frog) {
  frog.getTeeths = function() {
    return 0
  }
}

const mikeTheFrog = new Frog('mike')
withToad(mikeTheFrog)

console.log(mikeTheFrog.getTeeths())

jsmanifest

function Toad(name) {
  Frog.call(this, name)
  
  this.getTeeths = function() {
    return 0
  }
}

const kellyTheToad = new Toad('kelly')

jsmanifest

function Theme() {}

Theme.prototype.createStylesheet = function() {
  return {
    header: {
      color: '#333',
      fontStyle: 'italic',
      fontFamily: 'Roboto, sans-serif',
    },
    background: {

jsmanifest

{
  "header": {
    "color": "#333",
    "fontStyle": "italic",
    "fontFamily": "Roboto, sans-serif"
  },
  "background": { "backgroundColor": "#fff" },
  "button": { "backgroundColor": "#fff", "color": "#333" },
  "color": "#fff"
}

jsmanifest

function bloodTheme(originalTheme) {
  const originalStylesheet = originalTheme.createStylesheet()
  
  originalTheme.createStylesheet = function() {
    return {
      name: 'blood',
      ...originalStylesheet,
      header: {
        ...originalStylesheet.header,
        color: '#fff',