command pattern to build queries based on conditions

index.rb

module Index
  module_function

  def call(parent:, search_term:, sort:, direction:)
    queries = [
      parent_query(parent),
      search_query(search_term),
      sort_query(sort, direction)
    ]

    queries.inject(Owner.includes(:user)) do |query,collection|
      collection.call(query)
    end
  end

  private

  module_function

  def noop_call
    ->(collection) { collection }
  end

  def sort_query(sort_column, direction)
    return noop_call unless sort_column

    sort_direction = direction == 'DESC' ? :desc : :asc
    ->(collection) { collection.order(sort_column => sort_direction) }
  end

  def search_query(search_term)
    return noop_call unless search_term.present?

    ->(collection) { collection.search(search_term) }
  end

  def parent_query(parent)
    return noop_call unless parent?

    ->(collection) {
       collection
        .joins(:parent)
        .where(parents: { id: parent })
    }
  end
end