async queuing system that will retry failures

asycncQueues.js

// 50% success rate for each task
function unstableTask() {
  return new Promise((resolve, reject) => {
    setTimeout(() => {

      if (Math.random() < 0.5) {
        resolve('task succeeded!');
      } else {
        reject('task failed!')
      }
    }, 200);
  });
}

// set a global queue of unstable tasks
const tasks = [];
for (var i = 0; i < 5; i++) {
  tasks.push({
    task: unstableTask,
    number: i
  })
}

// async task retrieval, as in reading from database
function getTask() {
  return new Promise((resolve, reject) => {
    setTimeout(function () {
      resolve(tasks[0]);
    }, 500);
  });
}

// async task removal, as in updating database
function removeTask() {
  return new Promise((resolve, reject) => {
    setTimeout(function () {
      tasks.shift();
      resolve('done');
    }, 500);
  });
}

async function taskRunner() {
  while (tasks.length) {
    try {
      var taskObject = await getTask();
      var specificTask = await taskObject.task();
      console.log('yay', specificTask, taskObject.number);
      var removingTaskResult = await removeTask();
      console.log('removingTaskResult: ', removingTaskResult);
    } catch (err) {
      console.log('error, trying again', err, taskObject.number);
    }
  }
}

taskRunner();