require "cases/helper" require "models/invoice" require "models/line_item" class CacheKeyTest < ActiveRecord::TestCase def setup @invoice = Invoice.create LineItem.create(invoice: @invoice) @invoice.reload end def test_cache_key_changes_when_child_touched key = @invoice.cache_key @invoice.line_items[0].touch @invoice.reload assert_not_equal key, @invoice.cache_key end end