ambi/edition-es5/index.js

Ambi lets you execute any function ambidextrously; providing you the ability to execute any function (be it synchronous, asynchronous, returns, callbacks, promises) as if it returned a promise.

"use strict";
var __read = (this && this.__read) || function (o, n) {
    var m = typeof Symbol === "function" && o[Symbol.iterator];
    if (!m) return o;
    var i = m.call(o), r, ar = [], e;
    try {
        while ((n === void 0 || n-- > 0) && !(r = i.next()).done) ar.push(r.value);
    }
    catch (error) { e = { error: error }; }
    finally {
        try {
            if (r && !r.done && (m = i["return"])) m.call(i);
        }
        finally { if (e) throw e.error; }
    }
    return ar;
};
var __spreadArray = (this && this.__spreadArray) || function (to, from, pack) {
    if (pack || arguments.length === 2) for (var i = 0, l = from.length, ar; i < l; i++) {
        if (ar || !(i in from)) {
            if (!ar) ar = Array.prototype.slice.call(from, 0, i);
            ar[i] = from[i];
        }
    }
    return to.concat(ar || Array.prototype.slice.call(from));
};
Object.defineProperty(exports, "__esModule", { value: true });
// Import
var typechecker_1 = require("typechecker");
// Handle success case
function onSuccess(value) {
    // Reject if an error was returned
    if ((0, typechecker_1.isError)(value))
        return Promise.reject(value);
    // Success case, so return the value
    return value;
}
/**
 * Ambidextrously execute the method with the passed arguments.
 * If method.length > args.length, then ambi provides the method with a completion callback as the last expected argument.
 * @param method A method, that can either resolve synchronously, via a promise, or via a callback.
 * @param args The arguments to provide the function.
 * @returns The determined result.
 */
function ambi(method) {
    var args = [];
    for (var _i = 1; _i < arguments.length; _i++) {
        args[_i - 1] = arguments[_i];
    }
    /*
    Different ways functions can be called:
    ambi(function(a,next){next(null, a)}, a)
        > method.length > args.length
        > next will be provided automatically
    ambi(function(a){return a}, a)
        > method.length = args.length
        > no argument changes by ambi
    ambi(function(a){return a}, a, b)
        > method.length < args.length
        > no argument changes by ambi
    */
    try {
        // Inject a completion callback
        if (method.length > args.length) {
            return new Promise(function (resolve, reject) {
                var xargs = args
                    .slice()
                    // add the difference as undefined values
                    .concat(new Array(method.length - args.length - 1))
                    // add the completion callback
                    .concat([
                    function ambiCallback(err) {
                        var args = [];
                        for (var _i = 1; _i < arguments.length; _i++) {
                            args[_i - 1] = arguments[_i];
                        }
                        if (err)
                            return reject(err);
                        if (args.length === 1)
                            return resolve(args[0]);
                        return resolve(args);
                    },
                ]);
                method.apply(void 0, __spreadArray([], __read(xargs), false));
            }).then(onSuccess);
        }
        // Execute without a completion callback
        else {
            return Promise.resolve(method.apply(void 0, __spreadArray([], __read(args), false))).then(onSuccess);
        }
    }
    catch (err) {
        return Promise.reject(err);
    }
}
exports.default = ambi;