Haprog/loadScript.js

## loadScript.js
/**
 * Load the given script.
 * (appends a new &lt;script&gt; tag to the end of the main document's &lt;head&gt; tag)
 *
 * @param {string}  src   URL if the script to be loaded
 * @param {?Object} props Properties to be set on the script (e.g. async, defer, onload, onerror)
 * @param {?Object} attrs Attributes to be set on the script (e.g. id, data-*)
 * @returns {Promise}
 */
let loadScript = (src, props, attrs) => new Promise((resolve, reject) => {
	const script = document.createElement('script');
	script.src = src;
	for (const prop in props) {
		script[prop] = props[prop];
	}
	for (const attr in attrs) {
		script.setAttribute(attr, attrs[attr]);
	}
	script.addEventListener('load', () => resolve(script), false);
	script.addEventListener('error', () => reject(script), false);
	document.head.appendChild(script);
});

/**
 * Load the given script.
 * (appends a new &lt;script&gt; tag to the end of the main document's &lt;head&gt; tag)
 *
 * @param {string}  src   URL if the script to be loaded
 * @param {?Object} props Properties to be set on the script (e.g. async, defer, onload, onerror)
 * @param {?Object} attrs Attributes to be set on the script (e.g. id, data-*)
 */
let loadScriptLegacy = (src, props, attrs) => {
	const script = document.createElement('script');
	script.src = src;
	for (const prop in props) {
		script[prop] = props[prop];
	}
	for (const attr in attrs) {
		script.setAttribute(attr, attrs[attr]);
	}
	document.head.appendChild(script);
};
	/**
	* Load the given script.
	* (appends a new <script> tag to the end of the main document's <head> tag)
	*
	* @param {string} src URL if the script to be loaded
	* @param {?Object} props Properties to be set on the script (e.g. async, defer, onload, onerror)
	* @param {?Object} attrs Attributes to be set on the script (e.g. id, data-*)
	* @returns {Promise}
	*/
	let loadScript = (src, props, attrs) => new Promise((resolve, reject) => {
	const script = document.createElement('script');
	script.src = src;
	for (const prop in props) {
	script[prop] = props[prop];
	}
	for (const attr in attrs) {
	script.setAttribute(attr, attrs[attr]);
	}
	script.addEventListener('load', () => resolve(script), false);
	script.addEventListener('error', () => reject(script), false);
	document.head.appendChild(script);
	});

	/**
	* Load the given script.
	* (appends a new <script> tag to the end of the main document's <head> tag)
	*
	* @param {string} src URL if the script to be loaded
	* @param {?Object} props Properties to be set on the script (e.g. async, defer, onload, onerror)
	* @param {?Object} attrs Attributes to be set on the script (e.g. id, data-*)
	*/
	let loadScriptLegacy = (src, props, attrs) => {
	const script = document.createElement('script');
	script.src = src;
	for (const prop in props) {
	script[prop] = props[prop];
	}
	for (const attr in attrs) {
	script.setAttribute(attr, attrs[attr]);
	}
	document.head.appendChild(script);
	};