added mongoose hooks for removing email case sensitivity

src/api/models/migrateEmail.ts

@@ -0,0 +1,36 @@
+import mongoose from "mongoose";
+import dotenv from "dotenv";
+import { User } from "./User"; 
+
+dotenv.config();
+
+const runMigration = async () => {
+  try {
+    if (!process.env.MONGO_URI) throw new Error("Missing MONGO_URI in .env");
+    await mongoose.connect(process.env.MONGO_URI);
+    console.log("Connected to DB.");
+
+    const users = await User.find({});
+    console.log(`Checking ${users.length} users...`);
+
+    for (const user of users) {
+      if (user.email) {
+        user.email = user.email.toLowerCase(); 
+        try {
+            await user.save();
+            console.log(`Fixed: ${user.email}`);
+        } catch (err: any) {
+            console.log(`Skipped (Duplicate or Error): ${user.email}`);
+        }
+      }
+    }
+
+    console.log("Done!");
+    process.exit();
+  } catch (e) {
+    console.error(e);
+    process.exit(1);
+  }
+};
+
+runMigration();

src/api/models/userModel.ts

@@ -78,6 +78,25 @@ const userSchema = new Schema<IUser>(
   },
 );
 
+//Pre-save hook
+userSchema.pre("save", function (next){
+  if (this.isModified("email") && this.email){
+    this.email=this.email.toLowerCase();
+  }
+  next();
+});
+
+//Pre-find hook
+userSchema.pre(/^find/, function (next){
+  const query=this as any; 
+  const criteria=query.getFilter();
+
+  if (criteria.email && typeof criteria.email==="string"){
+    criteria.email=criteria.email.toLowerCase();
+  }
+  next();
+});
+
 const User = mongoose.model<IUser>("user", userSchema);
 type PopulatedUser = mongoose.Document<
   unknown,