From 99ea5e5641f8b480bfac6320f5fc12884b12fef0 Mon Sep 17 00:00:00 2001
From: "mw-middleware-labs-sandbox[bot]"
 <224139880+mw-middleware-labs-sandbox[bot]@users.noreply.github.com>
Date: Mon, 27 Apr 2026 05:34:42 +0000
Subject: [PATCH] Fix: Return HTTP 404 for missing users instead of HTTP 500

- Add 'abort' to Flask imports
- Check if username exists in user_data before lookup
- Return proper HTTP 404 with descriptive message for missing users
- Remove unreachable error handling code

This resolves the Python Backend Failure alert (Alert ID: 30146661)
where KeyError exceptions were causing HTTP 500 responses for
non-existent users (user6, user7), triggering error tracking alerts.

Root cause: Improper error handling in user_profile() function
Fix: Use abort(404) instead of raising KeyError for missing users
---
 flask/app.py | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/flask/app.py b/flask/app.py
index c30b439..e1bf8ec 100644
--- a/flask/app.py
+++ b/flask/app.py
@@ -7,7 +7,7 @@
     )
 )
 
-from flask import Flask, render_template, request, jsonify
+from flask import Flask, render_template, request, jsonify, abort
 import logging
 import os
 from datetime import datetime
@@ -60,10 +60,10 @@ def generate_exception():
 @app.route('/user/<username>')
 def user_profile(username):
     print(f"User profile requested for {username}")
-    test = user_data[username]
-    if not test:
-        raise
-    return jsonify({"message": f"Profile for {username}", "data": test})
+    if username not in user_data:
+        abort(404, description=f"User '{username}' not found")
+    user = user_data[username]
+    return jsonify({"message": f"Profile for {username}", "data": user})
 
 @app.route('/process', methods=['POST'])
 def process_user_data():
@@ -154,4 +154,4 @@ def user_stats(username):
     })
 
 if __name__ == '__main__':
-    app.run('0.0.0.0', 8010)
+    app.run('0.0.0.0', 8010)
\ No newline at end of file