From 48bf528fe5c7aff820e24273004e49e38968816f Mon Sep 17 00:00:00 2001
From: Vegard Kyrkjedelen Hovland <vegard@kyrkjedelen.no>
Date: Thu, 24 Apr 2025 10:22:02 +0200
Subject: [PATCH] feat: :goal_net: Write code to catch json-parsing errors

vf-300
---
 src/error/json-errors.ts           |  5 +++++
 src/main.ts                        |  9 ++++++++-
 src/middleware/error-middleware.ts | 15 +++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 src/error/json-errors.ts

diff --git a/src/error/json-errors.ts b/src/error/json-errors.ts
new file mode 100644
index 0000000..b42665f
--- /dev/null
+++ b/src/error/json-errors.ts
@@ -0,0 +1,5 @@
+type JsonError = SyntaxError;
+
+export function isJsonParsingError(error: unknown): error is JsonError {
+	return error instanceof SyntaxError;
+}
diff --git a/src/main.ts b/src/main.ts
index bf70ab9..2a17a73 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -3,6 +3,7 @@ import { hostOptions } from "@/src/enviroment";
 import {
 	errorHandler,
 	httpErrorHandler,
+	jsonParsingErrorHandler,
 	ormErrorHandler,
 	zodErrorHandler,
 } from "@/src/middleware/error-middleware";
@@ -44,7 +45,13 @@ api.use("/teamapplications", teamApplicationRouter);
 api.use("/teams", teamsRouter);
 
 // Error handling
-api.use(ormErrorHandler, zodErrorHandler, httpErrorHandler, errorHandler);
+api.use(
+	jsonParsingErrorHandler,
+	ormErrorHandler,
+	zodErrorHandler,
+	httpErrorHandler,
+	errorHandler,
+);
 
 api.listen(hostOptions.port, () => {
 	console.info(
diff --git a/src/middleware/error-middleware.ts b/src/middleware/error-middleware.ts
index 094e364..4af97e7 100644
--- a/src/middleware/error-middleware.ts
+++ b/src/middleware/error-middleware.ts
@@ -2,6 +2,21 @@ import { clientError, isHttpError, serverError } from "@/src/error/http-errors";
 import { isOrmError } from "@/src/error/orm-error";
 import type { ErrorRequestHandler } from "express";
 import { isZodErrorLike } from "zod-validation-error";
+import { isJsonParsingError } from "../error/json-errors";
+
+export const jsonParsingErrorHandler: ErrorRequestHandler = (
+	err,
+	_req,
+	res,
+	next,
+) => {
+	if (isJsonParsingError(err)) {
+		return res
+			.status(400)
+			.json({ error: true, message: `Invalid json: ${err.message}` });
+	}
+	next(err);
+};
 
 export const httpErrorHandler: ErrorRequestHandler = (err, _req, res, next) => {
 	if (isHttpError(err)) {