box-ui-elements-mlh/es/api/box-edit/promise.js.flow

Box UI Elements

// @flow
/**
 * NOTE: we don't use the NPM package directly because it has an unnecessary dependency on es6-promise + its commonjs format.
 * Returns the first promise in `promises` to successfully resolve.
 * If all fail, reject.
 * @see {@link https://github.com/jarofghosts/promise-one}
 */
function promiseOne(promises: Array<Promise<any>>): Promise<any> {
    const errors = [];
    let errorCount = 0;
    let error;

    return new Promise((resolve, reject) => {
        const pushErrors = idx => err => {
            errors[idx] = err;
            errorCount += 1;

            if (errorCount === promises.length) {
                error = new Error('no promises resolved');

                reject(error);
            }
        };

        promises.forEach((promise, idx) => {
            promise.then(resolve).catch(pushErrors(idx));
        });
    });
}

export default promiseOne;