From d53fd984e953f3ad055e039aa09a01a2b2a45a84 Mon Sep 17 00:00:00 2001
From: Gavin Sonntag <gsag@ucla.edu>
Date: Mon, 27 Apr 2026 15:59:18 -0700
Subject: [PATCH] fix: percent-encode track name in expo navigation

The expo dropdown built the track URL with `t.replace(/\s/g, '%20')`,
which only escapes spaces. A track name containing a slash (e.g.
"AI/ML") got navigated to /expo/AI/ML, which the route /expo/:track
interpreted as nested path segments and failed to match. Use
encodeURIComponent so spaces, slashes, and any other reserved URL
characters survive round-tripping through React Router.
---
 client/src/pages/Expo.tsx | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/client/src/pages/Expo.tsx b/client/src/pages/Expo.tsx
index a142247..f3ddb1f 100644
--- a/client/src/pages/Expo.tsx
+++ b/client/src/pages/Expo.tsx
@@ -123,7 +123,9 @@ const Expo = () => {
                     selected={track}
                     setSelected={setTrack}
                     onChange={(t) => {
-                        navigate('/expo/' + t.replace(/\s/g, '%20'));
+                        // encodeURIComponent handles spaces, slashes, and
+                        // any other reserved URL characters in track names.
+                        navigate('/expo/' + encodeURIComponent(t));
                     }}
                     options={challenges ?? []}
                     className="my-2 md:mx-0 mx-4"