expectContenType utility middleware

improve error logging middleware

options.json

@@ -61,7 +61,7 @@
         "broadcastLevel": 3
     },
     "databases": {
-        "messageBroker": {
+        "broker": {
             "load": false
         },
         "mariadb": {

src/server/Server.ts

@@ -266,12 +266,18 @@ class Server extends EventEmitter {
         req.remoteAddress = req.get('X-Forwarded-For') || req.socket.remoteAddress as string;
         next();
     }
-    
-    // eslint-disable-next-line no-unused-vars, @typescript-eslint/no-unused-vars
-    #logError (err: Error, req: Request, res: Response, _next: NextFunction) {
-        this.#logger.error(`Unhandled error:\n${err.stack || err}`);
-        if (!req.complete) 
-            res.status(500).send('An internal error was encountered');
+
+    #logError (err: Error, _req: Request, res: Response, _next: NextFunction) {
+        
+        if (err.name === 'SyntaxError' && err.message.includes('JSON') && err.stack?.includes('body-parser')) {
+            if (!res.closed) 
+                res.status(400).send(err.message);
+            // else quietly eat the error, user posted bad json
+        } else {
+            this.#logger.error(`Unhandled error:\n${err.stack || err}`);
+            if (!res.closed)
+                res.status(500).send('An internal error was encountered'); 
+        }
     }
 
     #logRequest (req: Request, res: Response, next: NextFunction) {

src/server/middleware/Util.ts

@@ -7,6 +7,8 @@ type FileFilterOptions = {
     fileExtensions?: FileExtensions[]
 }
 
+type ContentTypeOptions = string | string[];
+
 class UtilityMiddleware {
 
     constructor () {
@@ -21,6 +23,29 @@ class UtilityMiddleware {
         };
     }
 
+    static expectContentType (opts: ContentTypeOptions): MiddlewareFunction {
+        
+        if (!opts) 
+            throw new Error('Missing expected content type');
+
+        let options: string[] | null = null;
+        if ((opts instanceof Array))
+            options = opts;
+        else 
+            options = [ opts ];
+        
+        return (req: Request, res: Response, next: NextFunction): void => {
+            const contentType = req.get('content-type');
+            if (!contentType)
+                return void res.status(400).send('Must provide Content-Type');
+            
+            if (!options?.includes(contentType)) 
+                return void res.status(400).send(`Invalid content type; Expecting ${options?.join('/')}`);
+            
+            next();
+        };
+    }
+
     static denyFileTypes (options: FileFilterOptions): MiddlewareFunction {
         if (!options) 
             throw new Error('Need to supply options');

src/util/PermissionManager.ts

@@ -105,7 +105,7 @@ class PermissionManager {
                 PermissionManager.merge(to[key] as Permissions, from[key] as Permissions);
             // eslint-disable-next-line no-undefined
             } else if (!(key in to)) {
-                to[key] = from[key]; 
+                to[key] = from[key];
             }
         }
         return to;