export function loadScript(url: string): Promise<void> {
	return new Promise((resolve, reject) => {
		if (!document.querySelectorAll(`[src="${url}"]`).length) {
			try {
				let script = Object.assign(
					document.createElement("script"), {
						type: "text/javascript",
						src: url,
						onload: () => resolve(),
						onerror: e => reject(e)
					});
				document.body.appendChild(script);
			}
			catch (e) {
				reject(e);
			}
		} else {
			resolve();
		}
	});
}