From 019dd8c4da4895484f5984b7e2eb76e211030086 Mon Sep 17 00:00:00 2001
From: rxmox <omar52ramos@gmail.com>
Date: Sun, 1 Mar 2026 15:00:04 -0700
Subject: [PATCH] Fix guest join 409 error caused by duplicate email index

Remove redundant non-sparse index on user email field that prevented
multiple guest users (who have no email) from being created. The
sparse unique index from unique+sparse is sufficient.

Also improve E11000 error handling in joinEventAsUser and
joinEventAsGuest to distinguish between duplicate name vs duplicate
email errors instead of assuming all duplicates are name conflicts.
---
 .../src/controllers/event_controller.ts       | 32 ++++++++++++++-----
 shatter-backend/src/models/user_model.ts      |  1 -
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/shatter-backend/src/controllers/event_controller.ts b/shatter-backend/src/controllers/event_controller.ts
index f884d3a..122968c 100644
--- a/shatter-backend/src/controllers/event_controller.ts
+++ b/shatter-backend/src/controllers/event_controller.ts
@@ -206,10 +206,18 @@ export async function joinEventAsUser(req: Request, res: Response) {
     });
   } catch (e: any) {
     if (e.code === 11000) {
-      return res.status(409).json({
-        success: false,
-        msg: "This name is already taken in this event",
-      });
+      if (e.keyPattern?.name && e.keyPattern?.eventId) {
+        return res.status(409).json({
+          success: false,
+          msg: "This name is already taken in this event",
+        });
+      }
+      if (e.keyPattern?.email) {
+        return res.status(409).json({
+          success: false,
+          msg: "A user with this email already exists",
+        });
+      }
     }
     console.error("JOIN EVENT ERROR:", e);
     return res.status(500).json({ success: false, msg: "Internal error" });
@@ -297,10 +305,18 @@ export async function joinEventAsGuest(req: Request, res: Response) {
     });
   } catch (e: any) {
     if (e.code === 11000) {
-      return res.status(409).json({
-        success: false,
-        msg: "This name is already taken in this event",
-      });
+      if (e.keyPattern?.name && e.keyPattern?.eventId) {
+        return res.status(409).json({
+          success: false,
+          msg: "This name is already taken in this event",
+        });
+      }
+      if (e.keyPattern?.email) {
+        return res.status(409).json({
+          success: false,
+          msg: "A user with this email already exists",
+        });
+      }
     }
     console.error("JOIN GUEST ERROR:", e);
     return res.status(500).json({ success: false, msg: "Internal error" });
diff --git a/shatter-backend/src/models/user_model.ts b/shatter-backend/src/models/user_model.ts
index 521553e..78e76c9 100644
--- a/shatter-backend/src/models/user_model.ts
+++ b/shatter-backend/src/models/user_model.ts
@@ -45,7 +45,6 @@ const UserSchema = new Schema<IUser>(
       lowercase: true,
       unique: true,
       sparse: true, // allows multiple users without email (guests)
-      index: true,
       match: [
         /^[^\s@]+@[^\s@]+\.[^\s@]{2,}$/,
         "Please provide a valid email address",