'Cause ESNext is not enough

Pipelines

JS+ TypeScript

Object.keys(envars)
  .map(envar => `${envar}=${envars[envar]}`)
  .join(' ')
  |> `$ ${%}`
  |> chalk.dim(%, 'node', args.join(' '))
  |> console.log(%)

console.log(
  chalk.dim(
    `$ ${Object.keys(envars)
      .map(envar =>
        `${envar}=${envars[envar]}`)
      .join(' ')
    }`,
    'node',
    args.join(' ')
  )
);

Decorators

JS+ TypeScript

class C {
  message = "hello!";

  @bound
  m() {
    console.log(this.message);
  }
}

function bound(value, { name, addInitializer }) {
  addInitializer(function () {
    this[name] = this[name].bind(this);
  });
}

// TypeScript supports decorators behind an experimental flag
// JavaScript doesn't support decorators yet

And much more cool stuff…