Delays between promises in promise chain

Question

Let\'s say I am using the following code to run a couple of promises in series:

let paramerterArr = [\'a\',\'b\',\'c\',\'d\',\'e\',\'f\']
parameterArr.reduce         


        

Answer 1

To get a delay of at least 50ms, use Promise.all:

function delay(t) {
  return new Promise(function(resolve) {
    setTimeout(resolve, t);
  });
}
parameterArr.reduce(function(promise, item) {
  return promise.then(function() {
    return Promise.all([
      mySpecialFunction(item),
      delay(50)
    ]);
  });
}, Promise.resolve());