Added Error Handling middleware

src/app.ts

@@ -9,7 +9,8 @@ import staffRouter from "./services/staff/staff-router.js";
 import newsletterRouter from "./services/newsletter/newsletter-router.js";
 import versionRouter from "./services/version/version-router.js";
 import admissionRouter from "./services/admission/admission-router.js";
-
+// import { InitializeConfigReader } from "./middleware/config-reader.js";
+import { ErrorHandler } from "./middleware/error-handler.js";
 import Models from "./database/models.js";
 import { StatusCode } from "status-code-enum";
 import Config from "./config.js";
@@ -52,6 +53,8 @@ export function setupServer(): void {
     Models.initialize();
 }
 
+app.use(ErrorHandler);
+
 export function startServer(): Promise<Express.Application> {
     // eslint-disable-next-line no-magic-numbers
     const port = Config.PORT;

src/middleware/error-handler.ts

@@ -0,0 +1,48 @@
+import { Request, Response, NextFunction } from "express";
+import { StatusCode } from "status-code-enum";
+
+export class RouterError {
+    statusCode: number;
+    message: string;
+    // NOTE: eslint is required because the goal of RouterError.data is to "return any necessary data" - mostly used for debugging purposes
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    data?: any | undefined;
+    catchErrorMessage?: string | undefined;
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    constructor(statusCode?: number, message?: string, data?: any, catchErrorMessage?: string) {
+        this.statusCode = statusCode ?? StatusCode.ServerErrorInternal;
+        this.message = message ?? "Internal Server Error";
+        this.data = data;
+        if (catchErrorMessage) {
+            this.catchErrorMessage = catchErrorMessage;
+            console.error(catchErrorMessage);
+        } else {
+            this.catchErrorMessage = "";
+        }
+    }
+}
+
+// _next is intentionally not used in this middleware
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+export function ErrorHandler(error: RouterError, _req: Request, resp: Response, _next: NextFunction): void {
+    const statusCode: number = error.statusCode;
+    const message: string = error.message;
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const data: any | undefined = error.data;
+    const catchErrorMessage: string | undefined = error.catchErrorMessage;
+
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const jsonData: { [key: string]: any } = {
+        success: statusCode === StatusCode.SuccessOK,
+        error: message,
+    };
+    if (data) {
+        jsonData["data"] = data;
+    }
+    if (catchErrorMessage) {
+        jsonData["error_message"] = catchErrorMessage;
+    }
+
+    resp.status(statusCode).json(jsonData);
+}

src/services/admission/admission-router.ts

@@ -7,6 +7,8 @@ import Models from "../../database/models.js";
 import { hasElevatedPerms } from "../auth/auth-lib.js";
 import { ApplicantDecisionFormat } from "./admission-formats.js";
 import { StatusCode } from "status-code-enum";
+import { NextFunction } from "express-serve-static-core";
+import { RouterError } from "../../middleware/error-handler.js";
 
 const admissionRouter: Router = Router();
 
@@ -45,18 +47,21 @@ const admissionRouter: Router = Router();
  * @apiError (500: Internal Server Error) {String} InternalError occurred on the server.
  * @apiError (403: Forbidden) {String} Forbidden API accessed by user without valid perms.
  * */
-admissionRouter.get("/not-sent/", strongJwtVerification, async (_: Request, res: Response) => {
+admissionRouter.get("/not-sent/", strongJwtVerification, async (_: Request, res: Response, next: NextFunction) => {
     const token: JwtPayload = res.locals.payload as JwtPayload;
     if (!hasElevatedPerms(token)) {
-        return res.status(StatusCode.ClientErrorForbidden).send({ error: "Forbidden" });
+        return next(new RouterError(StatusCode.ClientErrorForbidden, "Forbidden"));
     }
     try {
         const filteredEntries: AdmissionDecision[] = await Models.AdmissionDecision.find({ emailSent: false });
         return res.status(StatusCode.SuccessOK).send(filteredEntries);
     } catch (error) {
-        console.error(error);
+        if (error instanceof Error) {
+            return next(new RouterError(undefined, undefined, undefined, error.message));
+        } else {
+            return next(new RouterError(undefined, undefined, undefined, `${error}`));
+        }
     }
-    return res.status(StatusCode.ClientErrorBadRequest).send({ error: "InternalError" });
 });
 
 /**
@@ -91,10 +96,10 @@ admissionRouter.get("/not-sent/", strongJwtVerification, async (_: Request, res:
  * @apiError (500: Internal Server Error) {String} InternalError occurred on the server.
  * @apiError (403: Forbidden) {String} Forbidden API accessed by user without valid perms.
  * */
-admissionRouter.put("/", strongJwtVerification, async (req: Request, res: Response) => {
+admissionRouter.put("/", strongJwtVerification, async (req: Request, res: Response, next: NextFunction) => {
     const token: JwtPayload = res.locals.payload as JwtPayload;
     if (!hasElevatedPerms(token)) {
-        return res.status(StatusCode.ClientErrorForbidden).send({ error: "Forbidden" });
+        return next(new RouterError(StatusCode.ClientErrorForbidden, "Forbidden"));
     }
     const updateEntries: ApplicantDecisionFormat[] = req.body as ApplicantDecisionFormat[];
     const ops = updateEntries.map((entry) => {
@@ -104,9 +109,12 @@ admissionRouter.put("/", strongJwtVerification, async (req: Request, res: Respon
         await Promise.all(ops);
         return res.status(StatusCode.SuccessOK).send({ message: "StatusSuccess" });
     } catch (error) {
-        console.log(error);
+        if (error instanceof Error) {
+            return next(new RouterError(undefined, undefined, undefined, error.message));
+        } else {
+            return next(new RouterError(undefined, undefined, undefined, `${error}`));
+        }
     }
-    return res.status(StatusCode.ClientErrorBadRequest).send("InternalError");
 });
 
 /**
@@ -133,21 +141,21 @@ admissionRouter.put("/", strongJwtVerification, async (req: Request, res: Respon
  *
  * @apiUse strongVerifyErrors
  */
-admissionRouter.get("/rsvp/:USERID", strongJwtVerification, async (req: Request, res: Response) => {
+admissionRouter.get("/rsvp/:USERID", strongJwtVerification, async (req: Request, res: Response, next: NextFunction) => {
     const userId: string | undefined = req.params.USERID;
 
     const payload: JwtPayload = res.locals.payload as JwtPayload;
 
     //Sends error if caller doesn't have elevated perms
     if (!hasElevatedPerms(payload)) {
-        return res.status(StatusCode.ClientErrorForbidden).send({ error: "Forbidden" });
+        return next(new RouterError(StatusCode.ClientErrorForbidden, "Forbidden"));
     }
 
     const queryResult: AdmissionDecision | null = await Models.AdmissionDecision.findOne({ userId: userId });
 
     //Returns error if query is empty
     if (!queryResult) {
-        return res.status(StatusCode.ClientErrorBadRequest).send({ error: "UserNotFound" });
+        return next(new RouterError(StatusCode.ClientErrorBadRequest, "UserNotFound"));
     }
 
     return res.status(StatusCode.SuccessOK).send(queryResult);
@@ -182,7 +190,7 @@ admissionRouter.get("/rsvp/:USERID", strongJwtVerification, async (req: Request,
  *
  * @apiUse strongVerifyErrors
  */
-admissionRouter.get("/rsvp", strongJwtVerification, async (_: Request, res: Response) => {
+admissionRouter.get("/rsvp", strongJwtVerification, async (_: Request, res: Response, next: NextFunction) => {
     const payload: JwtPayload = res.locals.payload as JwtPayload;
 
     const userId: string = payload.id;
@@ -191,7 +199,7 @@ admissionRouter.get("/rsvp", strongJwtVerification, async (_: Request, res: Resp
 
     //Returns error if query is empty
     if (!queryResult) {
-        return res.status(StatusCode.ClientErrorBadRequest).send({ error: "UserNotFound" });
+        return next(new RouterError(StatusCode.ClientErrorBadRequest, "UserNotFound"));
     }
 
     //Filters data if caller doesn't have elevated perms
@@ -232,12 +240,12 @@ admissionRouter.get("/rsvp", strongJwtVerification, async (_: Request, res: Resp
  *
  * @apiUse strongVerifyErrors
  */
-admissionRouter.put("/rsvp/", strongJwtVerification, async (req: Request, res: Response) => {
+admissionRouter.put("/rsvp/", strongJwtVerification, async (req: Request, res: Response, next: NextFunction) => {
     const rsvp: boolean | undefined = req.body.isAttending;
 
     //Returns error if request body has no isAttending parameter
     if (rsvp === undefined) {
-        return res.status(StatusCode.ClientErrorBadRequest).send({ error: "InvalidParams" });
+        return next(new RouterError(StatusCode.ClientErrorBadRequest, "InvalidParams"));
     }
 
     const payload: JwtPayload = res.locals.payload as JwtPayload;
@@ -248,12 +256,12 @@ admissionRouter.put("/rsvp/", strongJwtVerification, async (req: Request, res: R
 
     //Returns error if query is empty
     if (!queryResult) {
-        return res.status(StatusCode.ClientErrorBadRequest).send({ error: "UserNotFound" });
+        return next(new RouterError(StatusCode.ClientErrorBadRequest, "UserNotFound"));
     }
 
     //If the current user has not been accepted, send an error
     if (queryResult.status != DecisionStatus.ACCEPTED) {
-        return res.status(StatusCode.ClientErrorForbidden).send({ error: "NotAccepted" });
+        return next(new RouterError(StatusCode.ClientErrorForbidden, "NotAccepted"));
     }
 
     //If current user has been accepted, update their RSVP decision to "ACCEPTED"/"DECLINED" acoordingly
@@ -267,10 +275,9 @@ admissionRouter.put("/rsvp/", strongJwtVerification, async (req: Request, res: R
     );
 
     if (updatedDecision) {
-        //return res.status(StatusCode.SuccessOK).send(updatedDecision.toObject());
         return res.status(StatusCode.SuccessOK).send(updatedDecision);
     } else {
-        return res.status(StatusCode.ServerErrorInternal).send({ error: "InternalError" });
+        return next(new RouterError());
     }
 });