clearance_param_filtering.rb

# attr_accessible functionality
Clearance::UsersController.class_eval do
  alias_method :clearance_create, :create
  def create
    @valid_attributes = ["email", "password", "password_confirmation"]
    params[:user].reject! do |key, value|
      !@valid_attributes.include? key
    end
    clearance_create
  end
end

env.rb

# ...
Before do
  Dir[File.join(Rails.root, 'app/models/**/*.rb')].each do |model_path|
    klass = File.basename(model_path, '.rb').classify.constantize
    klass.collection.remove if klass.respond_to?(:collection)
  end
end

test_helper.rb

# ...
class Test::Unit::TestCase
  include Webrat::Matchers
  include RR::Adapters::TestUnit
end

class ActiveSupport::TestCase
  def setup
    clear_all_collections
  end

  def clear_all_collections
    Dir[File.join(Rails.root, 'app/models/**/*.rb')].each do |model_path|
      klass = File.basename(model_path, '.rb').classify.constantize
      klass.collection.remove if klass.respond_to?(:collection)
    end
  end
end

user.rb

class User
  include MongoMapper::Document

  key :email, String
  key :encrypted_password, String, :limit => 128
  key :salt, String, :limit => 128
  key :confirmation_token, String, :limit => 128
  key :remember_token, String, :limit => 128
  key :email_confirmed, Boolean, :default => false, :null => false

  # hack, mongo_mapper doesn't have attr_accessible
  def self.attr_accessible(*param);end

  include Clearance::User

end

users_controller_test.rb

require 'test_helper'

class UsersControllerTest < ActionController::TestCase
  tests Clearance::UsersController

  context "controlling mass assignment on the controller level" do

    setup do
      @protected = {:encrypted_password => "test",
                     :salt => "test",
                     :confirmation_token => "test",
                     :remember_token => "test",
                     :email_confirmed => "test"}
      @valid = {:email => "[email protected]",
                :password => "secret",
                :password_confirmation => "secret"}
      begin
        stub(ClearanceMailer).deliver_confirmation.with_any_args {true}
      rescue ArgumentError
        # why does this get thrown the first time I stub out the mailer
      end

      stub(ClearanceMailer).deliver_confirmation.with_any_args {true}
    end 

    context "on POST to :create with valid params" do
      setup do
        post :create, :user => {:email => "[email protected]",
             :password => "secret",
             :password_confirmation => "secret"}
      end

      should_change 'User.count', :by => 1
      should_redirect_to_url_after_create
    end
    [:encrypted_password, :salt, :confirmation_token,
     :remember_token, :email_confirmed].each do |key|
      context "on POST to :create with invalid params #{key}" do
        setup do
          @valid[key.to_sym] = @protected[key]
          post :create, :user => @valid
        end

        should "not allow assignment of #{key}" do
          assert_not_equal @protected[key], User.first.send(key)
        end
      end
    end
  end
end