backend: added exception handler for requests

backend/src/ExceptionHandler.ts

@@ -0,0 +1,15 @@
+import {ErrorRequestHandler, NextFunction, Request, Response} from 'express';
+
+export default function exceptionHandler(): ErrorRequestHandler {
+  return (err: any, req: Request, res: Response, next: NextFunction) => {
+    try {
+      console.error(err);
+      res.status(500).send('Internal server error: ' + err.message);
+    } catch (ex) {
+      console.error('Error in exception handler!');
+      console.error(ex);
+    } finally {
+      next();
+    }
+  };
+}

backend/src/main.ts

@@ -7,6 +7,7 @@ import {MangaUpdatesCache} from './cache/MangaUpdatesCache.js';
 import * as fs from 'fs';
 import {MangaDexCache} from './cache/MangaDexCache';
 import mangaDexRouter from './router/MangaDexRouter';
+import exceptionHandler from './ExceptionHandler';
 
 const config = JSON.parse(fs.readFileSync('config.json').toString());
 
@@ -26,6 +27,7 @@ app.use('/anilist', aniListRouter());
 app.use('/mangadex', mangaDexRouter(mangaDexCache));
 app.use('/mangaupdates', mangaUpdatesRouter(mangaUpdatesCache));
 app.use(express.static('_client')); //for production
+app.use(exceptionHandler());
 
 //start
 app.listen(config.port, config.host, () => {