    # File lib/chef/knife/cookbook_test.rb, line 45
          def run
            config[:cookbook_path] ||= Chef::Config[:cookbook_path]

            checked_a_cookbook = false
            if config[:all]
              cookbook_loader.each do |key, cookbook|
                checked_a_cookbook = true
                test_cookbook(key)
              end
            else
              @name_args.each do |cb|
                ui.info "checking #{cb}"
                next unless cookbook_loader.cookbook_exists?(cb)
                checked_a_cookbook = true
                test_cookbook(cb)
              end
            end
            unless checked_a_cookbook
              ui.warn("No cookbooks to test in #{Array(config[:cookbook_path]).join(',')} - is your cookbook path misconfigured?")
            end
          end