Prevent database access in specs

prevent_database_access.rb

# place in spec/support/prevent_database_access.rb

ActiveRecord::ConnectionAdapters::Mysql2Adapter.class_eval do
  def execute_with_prevent_database_access(sql, name=nil)
    if prevent_database_access?(sql)
      raise "You should only access the database in model and acceptance specs.
If you really need to you can use :db to grant access for that spec.

Offending query: \"#{sql}\""
    end

    execute_without_prevent_database_access(sql, name)
  end
  alias_method_chain :execute, :prevent_database_access

  def prevent_database_access?(sql)
    return false unless ActiveRecord::ConnectionAdapters::Mysql2Adapter.prevent_database_access

    sql =~ /^(SELECT|UPDATE|INSERT|DELETE)/
  end

  class << self
    attr_accessor :prevent_database_access
  end
end

RSpec.configure do |config|
  config.backtrace_clean_patterns << %r{#{__FILE__}}

  config.before :each do
    # Prevent database access unless :db is true or we're in a :request
    # or :model spec. Customize to suit your needs.
    ActiveRecord::ConnectionAdapters::Mysql2Adapter.prevent_database_access =
      !(example.metadata[:db] || [:request, :model].include?(example.metadata[:type]))
  end
end