ES6 async parallel execution

async-parallel.js

//mock a fs Object
let fs = {
  readFile: function(filename, cb){
    let randomTime = 100+Math.random()*1000>>0;
    
    setTimeout(()=>{
      cb(`hello ${filename}`)
    }, randomTime)
  }
}

// wrap fs#readFile into promise
let readFilePro = function(filename){
  return new Promise(function(resolve, reject) {
    fs.readFile(filename, (data, err) => {
      if(err) reject(err);
      resolve(data);
    })
  })
}

//function that execute readFile n times parallel
async function dbFuc(db) {
  let tmpArr = Array(10);
  tmpArr.fill(10);
  let names = tmpArr.map((x,i) => 'file'+i+'.txt');

  let promises = names.map((name) => readFilePro(name));

  let results = await Promise.all(promises);
  console.log(results);
}

//exec
dbFuc();

Thank you for sharing this! I needed to get promises working asynchronously with ES6 and I had never done it before. We were working against the clock so your working example was a lifesaver, with just the essentials and no fluff. Perfect!