| import isPromise from "./isPromise.mjs"; |
| |
| /** |
| * Similar to Array.prototype.reduce(), however the reducing callback may return |
| * a Promise, in which case reduction will continue after each promise resolves. |
| * |
| * If the callback does not return a Promise, then this function will also not |
| * return a Promise. |
| */ |
| export default function promiseReduce(values, callback, initialValue) { |
| return values.reduce(function (previous, value) { |
| return isPromise(previous) ? previous.then(function (resolved) { |
| return callback(resolved, value); |
| }) : callback(previous, value); |
| }, initialValue); |
| } |