amazon-cognito-identity-js/__tests__/util.js

Amazon Cognito Identity Provider JavaScript SDK

/**
 * Utility function that uses promises/resolve pattern to test asynchronous code in the Jest library
 * @param {object} obj - pass the entire object/file being test to resolve dependencies utilized within fn
 * @param {function} fn - name of the function that will be called.
 * @param {[args]} ...args - an array of arguments that varies with every function
 *
 * More information here:  https://jestjs.io/docs/asynchronous#callbacks
 **/

async function promisifyCallback(obj, fn, ...args) {
	return new Promise((resolve, reject) => {
		let callback = (err, data) => {
			err ? reject(err) : resolve(data);
		};
		try {
			//in case .apply() fails
			obj[fn].apply(obj, [...args, callback]);
		} catch (error) {
			reject(error);
		}
	});
}

exports.promisifyCallback = promisifyCallback;