github-pages-deploy-action/node_modules/graphql/jsutils/promiseReduce.mjs
2020-03-06 22:45:40 -05:00

17 lines
606 B
JavaScript

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);
}