module ThoughtBot::Shoulda::Controller::Helpers

def get_existing_record(res) # :nodoc:
  returning(instance_variable_get("@#{res.object}")) do |record|
    assert(record, "This test requires you to set @#{res.object} in your setup block")
  end
end

def instantiate_variables_from_assigns(*names, &blk)
  old = {}
  names = (@response.template.assigns.keys - SPECIAL_INSTANCE_VARIABLES) if names.empty?
  names.each do |name|
    old[name] = instance_variable_get("@#{name}")
    instance_variable_set("@#{name}", assigns(name.to_sym))
  end
  blk.call
  names.each do |name|
    instance_variable_set("@#{name}", old[name])
  end
end

def make_parent_params(resource, record = nil, parent_names = nil) # :nodoc:
  parent_names ||= resource.parents.reverse
  return {} if parent_names == [] # Base case
  parent_name = parent_names.shift
  parent = record ? record.send(parent_name) : parent_name.to_s.classify.constantize.find(:first)
  { :"#{parent_name}_id" => parent.to_param }.merge(make_parent_params(resource, parent, parent_names))
end