Flow + Babel = <3 or at least a slight improvement

flow-plus-babel.js

// @flow

type Person = {
  name: string,
  age: number
}

function getPeople (): Promise<Array<Person>> {
  const people: Array<Person> = [
    {name: 'Foo', age: 21},
    {name: 'Bar', age: 31},
    {name: 'Baz', age: 41}
  ]

  return new Promise((resolve) => {
    setTimeout(resolve(people), 1000)
  })
}

async function run () {
  const people: Array<Person> = await getPeople()
  const names: Array<string> = people.map((p: Person) => p.name)
}

run()