Devise #update_with_password

user.rb

class User < ActiveRecord::Base
  def update_with_password(params, *options)
    _current_password      = params[:current_password]
    _password              = params[:password]
    _password_confirmation = params[:password_confirmation]
    unless _current_password.blank?
      if _password.blank?
        errors.add(:password, "can't be blank")
        false
      else
        super
      end
    else
      super
    end
  end
end

user_spec.rb

describe User, "updating password" do
  it "requires the current password" do
    user = FactoryGirl.create(:user)
    user.update_with_password(:password => 'newpassword', 
                              :password_confirmation => 'newpassword').should be_false
    user.errors[:current_password].should include("can't be blank")
  end

  it "requires current_password to match the current password" do
    user = FactoryGirl.create(:user)
    user.update_with_password(:current_password => 'differentpassword', :password => 'foo',
                              :password_confirmation => 'foo').should be_false
    user.errors[:current_password].should include("is invalid")
  end

  it "requires password and password_confirmation to be present" do
    user = FactoryGirl.create(:user)
    user.error_on_blank_password = true
    user.update_with_password(:current_password => 'astrongpassword').should be_false
    user.errors[:password].should include("can't be blank")
  end
end