es-promise-ext/dist/wrap/wrap.js

Native promise extensions for javascript and typescript.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.default = wrap;
/**
 * Starts a promise with an asynchronous function that use a callback.
 *
 * @param {WrappedAsyncFunction<U>} wrappedAsyncFunctionWithCallback
 * - An asynchronous function that will be called, returning a result in callback.
 *
 * @return {Promise<U>}
 * The result returned from callback.
 *
 * @example
 * promiseWrap(asyncFunction);
 * // for asyncFunction accepting the callback as 1st parameter
 *
 * promiseWrap(cb => asyncFunction(1, 2, cb));
 * // for other asyncFunction accepting the callback as the rest parameter
 */
function wrap(wrappedAsyncFunctionWithCallback) {
    if (typeof wrappedAsyncFunctionWithCallback !== 'function') {
        throw new TypeError('Promise.wrap parameter 1 must be a function');
    }
    return new Promise((resolve) => {
        const callback = function (...args) {
            switch (args.length) {
                case 0:
                    resolve(undefined);
                    break;
                case 1:
                    resolve(args[0]);
                    break;
                default:
                    resolve(args);
                    break;
            }
        };
        wrappedAsyncFunctionWithCallback(callback);
    });
}