fetch-inject.js

/*! Fetch Inject | Copyright (C) VHS <vhsdev@tutanota.com> | @license Zlib */
const injector=function(i,n,j,e,c,t,s){t=n.createElement(j);j==="template"?(t.innerHTML=e.text,n.head.appendChild(t.content.cloneNode(!0)),c(e)):(s=n.getElementsByTagName(j)[0],t.appendChild(n.createTextNode(e.text)),t.onload=c(e),s?s.parentNode.insertBefore(t,s):n.head.appendChild(t))}; // prettier-ignore

export default async (inputs, promise, { fetch } = globalThis) => {
	const resources = [];
	const deferreds = promise ? [].concat(promise) : [];
	const thenables = [];
	inputs.forEach((input) =>
		deferreds.push(
			fetch(input)
				.then((res) => Promise.all([res.clone().text(), res.blob()]))
				.then(async ([text, blob]) => {
					resources.push({ text, blob });
				})
		)
	);
	await Promise.all(deferreds);
	resources.forEach((resource) =>
		thenables.push({
			then: (resolve) => {
				let type = 'script';
				const mimeToElementType = new Map([
					['text/html', 'template'],
					['text/css', 'style'],
					['application/javascript', 'script']
				]);
				for (const [mime, elementType] of mimeToElementType) {
					if (resource.blob.type.startsWith(mime)) {
						type = elementType;
						break;
					}
				}
				typeof document !== 'undefined'
					? injector(globalThis, document, type, resource, resolve)
					: resolve(resource);
			}
		})
	);
	return await Promise.all(thenables);
};