我正在使用 KSUIDs作为我的 Rails 应用程序中 UUID 的替代品。 michaelherold/ksuid-ruby将 KSUID 移植到 Ruby 并将它们实现为 ::ActiveRecord::Type::String
.除了使用 has_many :through associations
时的一个小错误外,一切都运行良好结合 class_name
.
我能够创建两个 rspec 测试来演示该错误。
工作测试
https://github.com/mattes/ksuid-ruby/blob/e545b1b251bd6430c454509475963a7845b1da0f/spec/cast1_spec.rb#L50-L58
# code excerpt from link above
class Patient < ActiveRecord::Base
act_as_ksuid :id
has_many :appointments
has_many :physicians, through: :appointments
end
bundle exec rspec ./spec/cast1_spec.rb # works as expected, tests pass
未通过测试
当我更新患者的预约关联以使用
class_name
时它会导致 TypeError: can't cast KSUID::Type
.https://github.com/mattes/ksuid-ruby/blob/e545b1b251bd6430c454509475963a7845b1da0f/spec/cast2_spec.rb#L46
# code excerpt from link above
class Patient < ActiveRecord::Base
act_as_ksuid :id
has_many :foobar, class_name: "Appointment" # <---- using class_name here
has_many :physicians, through: :foobar
end
bundle exec rspec ./spec/cast2_spec.rb # test fails
TypeError:
can't cast KSUID::Type
# ./spec/cast2_spec.rb:59:in `block (2 levels) in <top (required)>'
你能帮我找出问题并修复测试吗?要重现自己,请运行:
git clone https://github.com/mattes/ksuid-ruby.git
cd ksuid-ruby
git checkout cast_error
bundle install
bundle exec rspec ./spec/cast1_spec.rb # works
bundle exec rspec ./spec/cast2_spec.rb # fails
最佳答案
这看起来像一个 Rails 错误。
解析 through
时-association ( patient.physicians
) rails 查找与连接表名称相同的关系,并且由于没有 - 回退到字符串类型转换(=不需要类型转换,因此错误)。
使示例工作的一个技巧是添加关系:
class Physician < ActiveRecord::Base
act_as_ksuid :id
has_many :foobar, class_name: "Appointment"
has_many :patients, through: :foobar
has_many :appointments # <= this is not used in app, but rails now can correctly resolve types
end
Rails master (6.1-alpha) 有 pull request 36847合并,修复了某些情况,并输出了一个更容易理解的错误:
NotImplementedError: In order to correctly type cast Patient.id, Physician needs to define a :appointments association.
但它appears to break some other cases ,因此不确定 6.1 版本中会出现什么。所以现在上面的 hack 或带有 rails 版本保护的猴子补丁看起来是一个可行的解决方案。
附注。您的
ksuid/activerecord/schema_statements
将类型添加到 PostgreSQLAdapter
不管实际的适配器是什么。聚苯乙烯。您可以使用
bundler/inline
和 minitest/autorun
创建一个独立的示例(只需 ruby filename.rb
即可运行):require 'bundler/inline'
gemfile(ENV['INSTALL']=='1') do
source 'https://rubygems.org'
gem 'activerecord', '~>6.0.2' # also tested '~>5.2', '5.0' with same result, master with different error
gem 'sqlite3' # use , '~> 1.3.6' # for rails 5
gem 'ksuid', github: 'mattes/ksuid-ruby', ref:'e545b1b251bd6430c454509475963a7845b1da0f'
gem 'minitest'
end
require "active_record"
require "logger"
require "ksuid/activerecord"
require "ksuid/activerecord/table_definition"
# require "rails"
# require "ksuid/activerecord/schema_statements" # commented out to not load rails only to check Rails.env, instead:
require "active_record/connection_adapters/sqlite3_adapter"
::ActiveRecord::ConnectionAdapters::SQLite3Adapter::NATIVE_DATABASE_TYPES[:ksuid] = { name: "varchar", limit: 27 }
# require "ksuid/activerecord/quoting" # monkey-patch that fixes the error
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Base.logger = Logger.new(IO::NULL)
ActiveRecord::Schema.verbose = false
ActiveRecord::Schema.define do
create_table(:physicians, force: true, id: :ksuid)
create_table(:patients, force: true, id: :ksuid)
create_table(:appointments, force: true, id: :ksuid) {|t| t.ksuid :physician_id, :patient_id }
end
class Physician < ActiveRecord::Base
act_as_ksuid :id
has_many :foobar, class_name: "Appointment"
has_many :patients, through: :foobar
has_many :appointments # the hack
end
class Appointment < ActiveRecord::Base
act_as_ksuids :id, :physician_id, :patient_id
belongs_to :physician
belongs_to :patient
end
class Patient < ActiveRecord::Base
act_as_ksuid :id
has_many :appointments
has_many :physicians, through: :appointments
end
ActiveSupport.run_load_hooks(:active_record, ActiveRecord::Base)
require "minitest/autorun"
describe "ActiveRecord integration" do
it "loads all associations correctly" do
patient = Patient.create!
physician = Physician.create!
appointment = Appointment.create!(patient_id: patient.id, physician_id: physician.id)
expect(patient.id.class).must_equal KSUID::Type
expect(patient.physicians.first).must_equal physician
expect(physician.patients.first).must_equal patient
end
end
关于ruby-on-rails - Rails 自定义 ActiveRecord::Type 在 has_many 中使用 `class_name` 时失败:通过关联,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/60242514/