48 lines
1.1 KiB
JavaScript
48 lines
1.1 KiB
JavaScript
|
|
module.exports = {
|
|
promisify,
|
|
promisifyObject
|
|
};
|
|
|
|
/**
|
|
* Promisifies a function wich follows the (err, res) => {} pattern as last
|
|
* function argument and returns the promisified version.
|
|
*
|
|
* @param {Function} fn Function to promisify
|
|
* @return {Function} The promisified function
|
|
*/
|
|
function promisify(fn) {
|
|
return function(...args) {
|
|
let thisArg = this;
|
|
let orgCb = args[args.length - 1];
|
|
if (typeof orgCb !== 'function') orgCb = null;
|
|
|
|
return new Promise(function(resolve, reject) {
|
|
function cb(err, res) {
|
|
if (orgCb) orgCb(err, res);
|
|
err ? reject(err) : resolve(res);
|
|
}
|
|
|
|
if (orgCb)
|
|
args[args.length - 1] = cb;
|
|
else
|
|
args.push(cb);
|
|
|
|
fn.apply(thisArg, args);
|
|
});
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Promisifies object methods.
|
|
*
|
|
* @param {Object} obj Object to promisify
|
|
* @param {Array<String>} methods Array of method names to promisify
|
|
*/
|
|
function promisifyObject(obj, methods) {
|
|
for (let method of methods) {
|
|
let orgMethod = obj[method];
|
|
obj[method] = promisify(orgMethod);
|
|
}
|
|
}
|