fix test failed

Signed-off-by: Chang-Ning Tsai <changnit@amazon.com>

app.py

@@ -1,7 +1,5 @@
 # -*- coding: utf-8 -*-
-"""
-This is a simple cheatsheet webapp.
-"""
+"""This is a simple cheatsheet webapp."""
 
 import os
 from flask import Flask, abort, send_from_directory, render_template
@@ -77,12 +75,12 @@ def page_not_found(e):
 def static_proxy(path):
     """Find static files safely."""
     try:
-        safe_path = safe_join(ROOT, path)
-        return send_from_directory(ROOT, safe_path)
-    except (FileNotFoundError, IsADirectoryError):
+        return send_from_directory(ROOT, path)
+    except NotFound:
         # Handle file not found or directory errors
         return render_template("404.html"), 404
 
+
 @app.route("/")
 def index_redirection():
     """Redirecting index file."""
@@ -101,4 +99,4 @@ def acme(token):
 
 if __name__ == "__main__":
     # Only run the app in debug mode during development
-    app.run(debug=os.environ.get("FLASK_ENV") == "development")
+    app.run(debug=os.environ.get("FLASK_ENV") == "development")

app_test.py

@@ -138,6 +138,10 @@ def test_static_proxy(self):
             self.assertEqual(resp.status_code, 200)
             resp.close()
 
+        u = "notes/../conf.py"
+        _, code = static_proxy(u)
+        self.assertEqual(code, 404)
+
     def test_page_not_found(self):
         """Test page not found."""
         html, status_code = page_not_found(None)