A sample code of async/await by ES7

async.js

const panic = () => {
  return new Promise((resolve) => {
      throw new Error("throw.. ")
  })
}

const sleep = () => {
  return new Promise((resolve) => {
      setTimeout(function() {
          console.log("fin.")
          resolve("sleeped.")
      }, 1000)
  })
}

const finalTask = () => {
  return new Promise((resolve) => {
      console.log("finalTask")
      resolve("end.")
  })
}

(async () => {
    const r1 = await sleep()
    const rp = await panic()
    const r2 = await finalTask()
    console.log(["Result:", r1, r2, rp])
})()
.catch( err => {
    console.log("is error. -> " + err)
})

Above the code includes practices about;

• Use setTimeout to make sleep-function
• How to throw error
• and Error handling
• Get responses for each tasks