app/models/user.rb in devise_token_auth-0.1.15 vs app/models/user.rb in devise_token_auth-0.1.16

@@ -6,14 +6,15 @@
         :confirmable
 
   serialize :tokens, JSON
 
   # only validate unique emails among email registration users
-  validates_uniqueness_of :email, if: Proc.new { |u| u.provider == 'email' }
   validates_presence_of :email, if: Proc.new { |u| u.provider == 'email' }
   validates_presence_of :confirm_success_url, if: Proc.new {|u| u.provider == 'email'}
 
+  validate :unique_email_user, on: :create
+
   def valid_token?(client_id, token)
     return false unless self.tokens[client_id]['expiry'] > 2.weeks.ago
     return false unless BCrypt::Password.new(self.tokens[client_id]['token']) == token
 
     return true
@@ -26,9 +27,15 @@
   end
 
   # don't use default devise email validation
   def email_changed?
     false
+  end
+
+  def unique_email_user
+    if provider == 'email' and User.where(provider: 'email', email: email).count > 0
+      errors.add(:email, "Your email address is already in use")
+    end
   end
 
   def email_required?
     provider == 'email'
   end