bendc

function car() {
  return {
    start: function() {
      console.log("Engine on.")
    },
    accelerate: function() {
      console.log("Let's go!")
    }
  }
}

bendc

const define = (object, ...pairs) =>
  (Array.isArray(pairs[0]) ? pairs : [pairs]).reduce((accumulator, pair) => {
    const [ key, value ] = pair;
    return Object.defineProperty(accumulator, key, { value, enumerable: true }); 
  }, object);

bendc

const toRGB = (() => {
  const expand = hex =>
    hex.length < 7 ? hex.split("").reduce((a, b) => a + b + b) : hex;
  const convert = hex =>
    hex.match(/[\d\w]{2}/g).map(val => parseInt(val, 16));
  return hex => {
    const [r, g, b] = convert(expand(hex));
    return `rgb(${r}, ${g}, ${b})`;
  };
})();

bendc

const immutable = (() => {
  const getValue = obj => key => obj[key];
  const isObject = obj => Object(obj) === obj;
  const isMutable = obj => isObject(obj) && !Object.isFrozen(obj);

  return obj => {
    Object.keys(obj).map(getValue(obj)).filter(isMutable).forEach(immutable);
    return Object.freeze(obj);
  };
})();

bendc

const clone = map =>
  new Map(JSON.parse(JSON.stringify([...map])));

bendc

const odd = { a: 1, b: 3 };

const even = Object.entries(odd).reduce((object, pair) => {
  const [key, value] = pair;
  object[key] = value + 1;
  return object;
}, {});

console.log(even); // => { a: 2, b: 4 }

bendc

document.body.innerHTML = "<hello-message>Jane</hello-message>";

bendc

customElements.define("hello-message", class extends HTMLElement {
  constructor() {
    super();
    const root = this.attachShadow({mode: "open"});
    root.innerHTML = "Hello <slot></slot>";
  }
});

bendc

customElements.define("hello-message", class extends HTMLElement {
  constructor() {
    super();
    const root = this.attachShadow({mode: "open"});
    root.innerHTML = "Hello <slot></slot>";
  }

  static get observedAttributes() {
    return ["name"];
  }

bendc

const state = ["Buy milk", "Call Sarah", "Pay bills"];

customElements.define("todo-item", class extends HTMLElement {
  constructor() {
    super();
    const root = this.attachShadow({mode: "open"});
    root.innerHTML = ` 
      <label>
        <input type=checkbox>
        <slot></slot>