fix middleware stuff

backend/src/index.js

@@ -47,19 +47,18 @@ app.use(express.static(path.join(__dirname, "public"), {
 app.use("/api/docs", swaggerUi.serve, swaggerUi.setup(specs));
 app.use("/api", apiRouter);
 
-app.use((req, res) => {
-  res.status(404).send("Not Found");
-})
+app.use((_req, res, next) => {
+  if (res.error == null) {
+    return res.status(404).send("Not Found");
+  } else {
+    const err = res.error;
+    if (err instanceof ApiError) {
+      return res.status(err.status).json({ status: "error", error: err.message });
+    }
 
-// has to be last
-app.use((_req, res, _next) => {
-  const err = res.error;
-  if (err instanceof ApiError) {
-    return res.status(err.status).json({ status: "error", error: err.message });
+    console.error(err);
+    res.status(500).json({ status: "error", error: "Internal server error" });
   }
-
-  console.error(err);
-  res.status(500).json({ status: "error", error: "Internal server error" });
 })
 
 const server = https.createServer({