How do you synchronously resolve a chain of es6 promises?

If you are using es6, you can achieve this using array.reduce. I think quite neatly.

const functions = [/* array of functions which return promises */];
const finalPromise = functions.reduce(async (promise, asyncFn) => {
  await promise;
  return asyncFn();
}, Promise.resolve());

Your "non-loop" solution shouldn't work either. You have to pass a function to .then, not a promise:

var p = Promise.resolve();
for (var i=1; i<=10; i++) {
  (function(i) {
      p = p.then(function() {
          return promiseReturner(i);
      });
  }(i));
}

If that function returns a promise, then you get that chaining effect.

More info about promises on MDN.

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Can be simplified with let (and arrow functions):

var p = Promise.resolve();
for (let i=1; i<=10; i++) {
    p = p.then(() => promiseReturner(i));
}

Or .bind (which is ES5):

var p = Promise.resolve();
for (var i=1; i<=10; i++) {
    p = p.then(promiseReturner.bind(null, i));
}