Rspec should_not access_database

gistfile1.rb

class AccessDatabase
  def initialize
    @query_count = 0
    @query_sql = []
  end

  def matches?(target)
    subscription = ActiveSupport::Notifications.subscribe(/^sql\./) do |*args|
      @query_count += 1
      @query_sql << args.last[:sql]
    end
    target.call
    @query_count > 0
  end

  def failure_message_for_should
    "expected block to access database"
  end

  def failure_message_for_should_not
    "expected block not to access database, the following queries were run:\n#{@query_sql.join("\n")}"
  end
end

def access_database
  AccessDatabase.new
end

Stolen from https://gist.github.com/1305807 and rewritten for rspec