Nestjs Response Serialization with array of objects

I would recommend to directly put the @Exclude decorators on your entity class User instead of duplicating the properties in UserResponse. The following answer assumes you have done so.

---

Flat Response

If you have a look at the code of the ClassSerializerInterceptor, you can see that it automatically handles arrays:

return isArray
  ? (response as PlainLiteralObject[]).map(item =>
      this.transformToPlain(item, options),
    )
  : this.transformToPlain(response, options);

However, it will only transform them, if you directly return the array, so return users instead of return {users: users}:

@UseInterceptors(ClassSerializerInterceptor)
@Get('all')
async findAll(): Promise<User> {
    return this.userService.findAll()
}

---

Nested Response

If you need the nested response, then your way is a good solution. Alternatively, you can call class-transformer's serialize directly instead of using the ClassSerializerInterceptor. It also handles arrays automatically:

import { serialize } from 'class-transformer';

@Get('all')
async findAll(): Promise<UsersResponse> {
  const users: User[] = await this.userService.findAll();
  return {users: serialize(users)};
}