chore: Split error handler middleware to a seperate file

backend/src/app.ts

@@ -1,10 +1,9 @@
 
-import express, { NextFunction, Request, Response } from 'express';
+import express from 'express';
 import helmet from 'helmet';
 import cors from 'cors';
 import cookieParser from 'cookie-parser';
 import dotenv from 'dotenv';
-import * as Sentry from '@sentry/node';
 
 dotenv.config();
 import { PORT, NODE_ENV, SITE_URL } from './config';
@@ -30,8 +29,8 @@ import {
   integrationAuth as integrationAuthRouter
 } from './routes';
 import { getLogger } from './utils/logger';
-import RequestError, { LogLevel } from './utils/requestError';
+import { catchUnroutedRequests } from './middleware/catchUnroutedRequests';
-import { InternalServerError, RouteNotFoundError } from './utils/errors';
+import { RouteNotFoundError } from './utils/errors';
 
 export const app = express();
 
@@ -81,27 +80,7 @@ app.use((req, res, next)=>{
 })
 
 //* Error Handling Middleware (must be after all routing logic)
-app.use((error: RequestError|Error, req: Request, res: Response, next: NextFunction)=>{
+app.use(catchUnroutedRequests)
-  if(res.headersSent) return next();
-  //TODO: Find better way to type check for error. In current setting you need to cast type to get the functions and variables from RequestError
-  if(!(error instanceof RequestError)){
-      error = InternalServerError({context: {exception: error.message}, stack: error.stack})
-      getLogger('backend-main').log((<RequestError>error).levelName.toLowerCase(), (<RequestError>error).message)
-  }
-
-  //* Set Sentry user identification if req.user is populated
-  if(req.user !== undefined && req.user !== null){
-    Sentry.setUser({ email: req.user.email })
-  }
-  //* Only sent error to Sentry if LogLevel is one of the following level 'ERROR', 'EMERGENCY' or 'CRITICAL'
-  //* with this we will eliminate false-positive errors like 'BadRequestError', 'UnauthorizedRequestError' and so on
-  if([LogLevel.ERROR, LogLevel.EMERGENCY, LogLevel.CRITICAL].includes((<RequestError>error).level)){
-    Sentry.captureException(error)
-  }
-  
-  res.status((<RequestError>error).statusCode).json((<RequestError>error).format(req))
-  next()
-})
 
 
 export const server = app.listen(PORT, () => {

backend/src/middleware/catchUnroutedRequests.ts

@@ -0,0 +1,29 @@
+import { ErrorRequestHandler } from "express";
+
+import * as Sentry from '@sentry/node';
+import { InternalServerError } from "../utils/errors";
+import { getLogger } from "../utils/logger";
+import RequestError, { LogLevel } from "../utils/requestError";
+
+
+export const catchUnroutedRequests: ErrorRequestHandler = (error: RequestError|Error, req, res, next) => {
+    if(res.headersSent) return next();
+    //TODO: Find better way to type check for error. In current setting you need to cast type to get the functions and variables from RequestError
+    if(!(error instanceof RequestError)){
+        error = InternalServerError({context: {exception: error.message}, stack: error.stack})
+        getLogger('backend-main').log((<RequestError>error).levelName.toLowerCase(), (<RequestError>error).message)
+    }
+    
+    //* Set Sentry user identification if req.user is populated
+    if(req.user !== undefined && req.user !== null){
+        Sentry.setUser({ email: req.user.email })
+    }
+    //* Only sent error to Sentry if LogLevel is one of the following level 'ERROR', 'EMERGENCY' or 'CRITICAL'
+    //* with this we will eliminate false-positive errors like 'BadRequestError', 'UnauthorizedRequestError' and so on
+    if([LogLevel.ERROR, LogLevel.EMERGENCY, LogLevel.CRITICAL].includes((<RequestError>error).level)){
+        Sentry.captureException(error)
+    }
+    
+    res.status((<RequestError>error).statusCode).json((<RequestError>error).format(req))
+    next()
+}