Add admin fyi for batch emails

package.json

@@ -1,6 +1,6 @@
 {
   "name": "registration",
-  "version": "2.3.1",
+  "version": "2.3.2",
   "description": "Powerful and extensible registration system for hackathons and other large events",
   "main": "server/app.js",
   "scripts": {

server/routes/api/settings.ts

@@ -283,7 +283,7 @@ settingsRoutes.route("/email_content/:type/rendered")
 settingsRoutes.route("/send_batch_email")
 	.post(isAdmin, uploadHandler.any(), async (request, response) => {
 		let filter = JSON.parse(request.body.filter);
-		let subject = request.body.subject;
+		let subject = request.body.subject as string;
 		let markdownContent = request.body.markdownContent;
 		if (typeof filter !== "object") {
 			return response.status(400).json({
@@ -313,6 +313,22 @@ settingsRoutes.route("/send_batch_email")
 				text
 			});
 		}
+
+		let admins = await User.find({ admin: true });
+		for (let user of admins) {
+			let html: string = await renderEmailHTML(markdownContent, user);
+			let text: string = await renderEmailText(html, user, true);
+			subject = `[Admin FYI] ${subject}`;
+			text = `${filter.toString()}\n${text}`;
+			text = `${filter.toString()}<br>${text}`;
+			emails.push({
+				from: config.email.from,
+				to: user.email,
+				subject,
+				html,
+				text
+			});
+		}
 		try {
 			await sendBatchMailAsync(emails);
 		} catch (e) {