我有一个要使用 counter_cache 的 Padrino 应用程序。我使用 ActiveRecord 作为我的 ORM。在我的存储库模型中，我想记录与给定存储库关联的贡献数量。以下是相关型号：
class Repository < ActiveRecord::Base
has_many :contributions, autosave: true
has_many :users, through: :contributions
validates :full_name, presence: true, uniqueness: true
end
class Contribution < ActiveRecord::Base
belongs_to :user
belongs_to :repository, counter_cache: true
end
class User < ActiveRecord::Base
has_many :contributions
has_many :repositories, through: :contributions
validates :username, presence: true, uniqueness: true
end
架构如下：
create_table "contributions", :force => true do |t|
t.integer "user_id"
t.integer "repository_id"
end
create_table "repositories", :force => true do |t|
t.string "full_name"
t.integer "contributions_count", :default => 0
end
create_table "users", :force => true do |t|
t.string "username"
end
我在 Rspec 中创建了一个测试来检查贡献计数是否正确更新。但是，我无法让它通过。这是规格：
describe "when a new contribution is created" do
it "updates the counter cache" do
repo = Repository.create(full_name: "sample_repo")
user = User.create(username: "sample_user")
expect {
Contribution.create(user: user, repository: repo)
}.to change {repo.contributions_count }.by(1)
end
end
当我运行规范时，出现以下故障：
1) Repository when a new contribution is created updates the counter cache
Failure/Error: expect {
result should have been changed by 1, but was changed by 0
# ./spec/models/repository_spec.rb:43:in `block (3 levels) in <top (required)>'
我也尝试在控制台中创建贡献，它没有更新存储库 counter_cache。我已经尝试了很多东西，但似乎无法弄清楚如何让它正常工作。任何帮助，将不胜感激。谢谢。