fix(backend): normalize emails to lowercase in dtos (SCRUM-307)

Author: bernhaaard

backend/src/modules/admin/dto/create-admin.dto.ts

@@ -1,5 +1,6 @@
 import { ApiProperty } from '@nestjs/swagger';
 import { IsEmail, IsString, IsNotEmpty } from 'class-validator';
+import { Transform } from 'class-transformer';
 import { IsAllowedEmailDomain } from '../../../common/validators/allowed-email-domains.validator';
 
 export class CreateAdminDto {
@@ -10,6 +11,9 @@ export class CreateAdminDto {
   })
   @IsEmail()
   @IsNotEmpty()
+  @Transform(({ value }: { value: unknown }) =>
+    typeof value === 'string' ? value.toLowerCase() : (value as string),
+  )
   @IsAllowedEmailDomain({
     message: 'Email must be from an allowed domain',
   })

backend/src/modules/admin/dto/supervisors-bulk-import.dto.ts

@@ -1,4 +1,4 @@
-import { Type } from 'class-transformer';
+import { Type, Transform } from 'class-transformer';
 import {
   IsEmail,
   IsString,
@@ -19,6 +19,9 @@ export class SupervisorDto {
   })
   @IsEmail()
   @IsNotEmpty()
+  @Transform(({ value }: { value: unknown }) =>
+    typeof value === 'string' ? value.toLowerCase() : (value as string),
+  )
   email: string;
 
   @ApiPropertyOptional({

backend/src/modules/auth/strategies/clerk-registration.strategy.ts

@@ -121,7 +121,7 @@ export class ClerkRegistrationStrategy extends PassportStrategy(Strategy, 'clerk
       // For registration, extract and return the claims without DB lookup
       return {
         clerk_id: payload.sub,
-        email: payload.email,
+        email: payload.email.toLowerCase(),
         exp: payload.exp,
       };
     } catch (error) {

backend/src/modules/requests/supervision/dto/create-supervision-request.dto.ts

@@ -1,5 +1,6 @@
 import { ApiPropertyOptional } from '@nestjs/swagger';
 import { IsEmail, IsOptional, IsUUID } from 'class-validator';
+import { Transform } from 'class-transformer';
 import { IsAllowedEmailDomain } from '../../../../common/validators/allowed-email-domains.validator';
 
 export class CreateSupervisionRequestDto {
@@ -18,6 +19,9 @@ export class CreateSupervisionRequestDto {
   })
   @IsOptional()
   @IsEmail()
+  @Transform(({ value }: { value: unknown }) =>
+    typeof value === 'string' ? value.toLowerCase() : (value as string),
+  )
   @IsAllowedEmailDomain({
     message: 'Email must be from an allowed domain',
   })

backend/src/modules/users/dto/create-user.dto.ts

@@ -1,5 +1,6 @@
 import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
 import { IsEmail, IsOptional, IsString, IsNotEmpty } from 'class-validator';
+import { Transform } from 'class-transformer';
 
 export class CreateUserDto {
   @ApiProperty({
@@ -9,6 +10,9 @@ export class CreateUserDto {
   })
   @IsEmail()
   @IsNotEmpty()
+  @Transform(({ value }: { value: unknown }) =>
+    typeof value === 'string' ? value.toLowerCase() : (value as string),
+  )
   email: string;
 
   @ApiPropertyOptional({

backend/src/modules/users/dto/update-user.dto.ts

@@ -1,5 +1,6 @@
 import { ApiPropertyOptional } from '@nestjs/swagger';
 import { IsEmail, IsOptional, IsString } from 'class-validator';
+import { Transform } from 'class-transformer';
 
 export class UpdateUserDto {
   @ApiPropertyOptional({
@@ -8,6 +9,9 @@ export class UpdateUserDto {
   })
   @IsEmail()
   @IsOptional()
+  @Transform(({ value }: { value: unknown }) =>
+    typeof value === 'string' ? value.toLowerCase() : (value as string),
+  )
   email?: string;
 
   @ApiPropertyOptional({