• Home

  • Custom Ecommerce
  • Application Development
  • Database Consulting
  • Cloud Hosting
  • Systems Integration
  • Legacy Business Systems
  • Security & Compliance
  • GIS

  • Expertise

  • About Us
  • Our Team
  • Clients
  • Careers

  • Blog

  • EpiTrax

  • VisionPort

  • Contact
  • Our Blog

    Ongoing observations by End Point Dev people

    Rails: Devise and Email Capitalization

    Steph Skardal

    By Steph Skardal
    November 30, 2012

    This week, I found a bug for one of our Rails clients that was worth a quick blog post. The client website runs on Rails 3.2.8 with ActiveRecord and PostgreSQL, uses RailsAdmin for an admin interface, Devise for user authentication, and CanCan for user authorization. Before we found the bug, our code looked something like this:

    class SomeController < ApplicationController
      def some_method
        user = User.find_or_create_by_email(params[:email])
        # do some stuff with the user provided parameters
        if user.save
          render :json => {}
        else
          render :json => {}, :status => 500
        end
      end
    end
    

    It’s important to note that the 500 error wasn’t reported to the website visitor — there were no visible UI notes to indicate the process had failed. But besides that, this code looks sane, right? We are looking up or creating a user from the provided email, updating the user parameters, and then attempting to save. For the most part, this worked fine, until we came across a situation where the user data was not getting updated properly.

    Looking through the logs, I found that the user experiencing the bug was entering mixed caps emails, for example, Steph@endpoint.com. Let’s walk through the code in this scenario:

    First, a new user is created because there is no user in the system with the exact email Steph@endpoint.com. However, a user does exist in the system tied to steph@endpoint.com.

    user = User.find_or_create_by_email(params[:email]) # with "Steph@endpoint.com" 
    

    No problems here:

    # do some stuff with the user provided parameters
    

    Below is where the issue is coming up. Devise, our user authentication gem, automatically downcases (lowercases) all emails when they are stored in the database. There is already a user tied to steph@endpoint.com, so user.save fails, a 500 error is thrown, but as an end-user, I don’t see anything to indicate that my AJAX call failed.

    if user.save
    

    The moral of this story is that it’s important to (a) understand how plugins manipulate user data automatically (in this case Devise automatically filters the email) and (b) test a variety of use cases (in this case, we hadn’t considered testing mixed caps emails). Our updated code looks something like this, which downcases emails and upon failure, adds more to the logs for additional unexpected user update failures:

    class SomeController < ApplicationController
      def some_method
        user = User.find_or_create_by_email(params[:email].downcase)
        # do some stuff with the user provided parameters
        if user.save
          render :json => {}
        else
          render :json => {}, :status => 500
          Rails.logger.warn "USER ERROR: #{user.errors.full_messages} #{user.attributes.inspect}"
        end
      end
    end
    

    rails


    Comments