Add error handling to node_helper startup sequence (#2945)

Fixes https://github.com/MichMich/MagicMirror/issues/2944

Also splits the Server js into a constrcutor and an open call to remove
one callback parameter :-)

Co-authored-by: veeck <michael@veeck.de>

CHANGELOG.md

@@ -34,6 +34,7 @@ Special thanks to: @rejas, @sdetweil
 
 - Correctly show apparent temperature in SMHI weather provider
 - Ensure updatenotification module isn't shown when local is _ahead_ of remote
+- Handle node_helper errors during startup (#2944)
 - Possibility to change FontAwesome class in calendar, so icons like `fab fa-facebook-square` works.
 - Fix cors problems with newsfeed articles (as far as possible), allow disabling cors per feed with option `useCorsProxy: false` (#2840)
 

js/app.js

@@ -223,27 +223,38 @@ function App() {
 			}
 
 			loadModules(modules, function () {
-				httpServer = new Server(config, function (app, io) {
+				httpServer = new Server(config);
+				const { app, io } = httpServer.open();
 				Log.log("Server started ...");
 
 				const nodePromises = [];
-
 				for (let nodeHelper of nodeHelpers) {
 					nodeHelper.setExpressApp(app);
 					nodeHelper.setSocketIO(io);
+
+					try {
 						nodePromises.push(nodeHelper.start());
+					} catch (error) {
+						Log.error(`Error when starting node_helper for module ${nodeHelper.name}:`);
+						Log.error(error);
+					}
 				}
 
-					Promise.allSettled(nodePromises).then(() => {
-						Log.log("Sockets connected & modules started ...");
+				Promise.allSettled(nodePromises).then((results) => {
+					// Log errors that happened during async node_helper startup
+					results.forEach((result) => {
+						if (result.status === "rejected") {
+							Log.error(result.reason);
+						}
+					});
 
+					Log.log("Sockets connected & modules started ...");
 					if (typeof callback === "function") {
 						callback(config);
 					}
 				});
 			});
 		});
-		});
 	};
 
 	/**

js/server.js

@@ -5,7 +5,6 @@
  * MIT Licensed.
  */
 const express = require("express");
-const app = require("express")();
 const path = require("path");
 const ipfilter = require("express-ipfilter").IpFilter;
 const fs = require("fs");
@@ -19,14 +18,15 @@ const Utils = require("./utils.js");
  * Server
  *
  * @param {object} config The MM config
- * @param {Function} callback Function called when done.
  * @class
  */
-function Server(config, callback) {
+function Server(config) {
+	const app = express();
 	const port = process.env.MM_PORT || config.port;
 	const serverSockets = new Set();
-
 	let server = null;
+
+	this.open = function () {
 		if (config.useHttps) {
 			const options = {
 				key: fs.readFileSync(config.httpsPrivateKey),
@@ -52,7 +52,6 @@ function Server(config, callback) {
 		});
 
 		Log.log(`Starting server on port ${port} ... `);
-
 		server.listen(port, config.address || "localhost");
 
 		if (config.ipWhitelist instanceof Array && config.ipWhitelist.length === 0) {
@@ -69,8 +68,8 @@ function Server(config, callback) {
 				res.status(403).send("This device is not allowed to access your mirror. <br> Please check your config.js or config.js.sample to change this.");
 			});
 		});
-	app.use(helmet(config.httpHeaders));
 
+		app.use(helmet(config.httpHeaders));
 		app.use("/js", express.static(__dirname));
 
 		// TODO add tests directory only when running tests?
@@ -127,9 +126,11 @@ function Server(config, callback) {
 			res.send(html);
 		});
 
-	if (typeof callback === "function") {
-		callback(app, io);
-	}
+		return {
+			app,
+			io
+		};
+	};
 
 	this.close = function () {
 		for (const socket of serverSockets.values()) {