在 Rails 中加载自定义装置

Question

我们正在尝试为使用与 ActiveRecord::Base 不同的数据库连接（在本例中继承自 Foo::Base）的一组模型加载固定装置。

我们创建了包含在 ActiveSupport::TestCase 中的这个模块，并指定了 .yml 文件的路径，例如foo_fitures :all。这对于运行的第一个测试非常有用。定义夹具访问器并在数据库中找到记录。但是对于后续的测试，数据库中没有记录。

module Foo::Fixtures
  extend ActiveSupport::Concern

  included do
    setup :setup_foo_fixtures
    teardown :teardown_foo_fixtures

    class_attribute :foo_fixture_path
    class_attribute :foo_fixture_table_names

    self.foo_fixture_table_names = []
  end

  module ClassMethods
    def foo_fixtures(*fixture_names)
      if fixture_names.first == :all
        fixture_names = Dir[foo_fixture_path.join("**/*.yml")].map { |f| File.basename(f, ".yml") }
      else
        fixture_names = fixture_names.flatten.map { |n| n.to_s }
      end

      self.foo_fixture_table_names |= fixture_names
      require_fixture_classes(fixture_names)
      setup_fixture_accessors(fixture_names)
    end
  end

  def setup_foo_fixtures
    @loaded_fixtures.merge!(load_foo_fixtures)
  end

  def teardown_foo_fixtures
    Foo::Base.clear_active_connections!
  end

  private

  def load_foo_fixtures
    foo_classes = Foo::Base.subclasses.flat_map { |klass| klass.abstract_class ? klass.subclasses : klass }
    class_names = foo_classes.each_with_object({}) do |klass, memo|
      memo[klass.table_name.to_sym] = klass if klass.table_name.present? && foo_fixture_table_names.include?(klass.table_name)
    end
    foo_fixtures = ActiveRecord::Fixtures.create_fixtures(foo_fixture_path, foo_fixture_table_names, class_names) do
      Foo::Base.connection
    end
    Hash[foo_fixtures.map { |f| [f.name, f] }]
  end
end

Rails 的夹具系统有点复杂，我无法弄清楚我们缺少什么来确保加载额外的夹具。

Answer 1

好的。看起来可能是交易从数据库中删除了我们的固定装置。我的猜测是事务在我们的代码加载到夹具之前就已经开始了，所以这就是为什么它们在第一次测试时就在那里，但在第二次测试时就消失了。

所以我们改变了策略，现在我们只钩入load_fixtures 和fixtures。这工作得很好。

module FooFixtures
  module ClassMethods
    def foo_fixture_classes
      collect_subclasses = ->(k) { k.abstract_class ? k.subclasses.flat_map(&collect_subclasses) : k }
      Foo::Base.subclasses.flat_map(&collect_subclasses)
    end

    def foo_fixture_path
      Rails.root.join("test/foo_fixtures")
    end

    def foo_fixture_table_names
      Dir[foo_fixture_path.join("**/*.yml")].map { |f| File.basename(f, ".yml") }
    end

    def fixtures(*fixture_names)
      super
      if fixture_names.first == :all
        require_fixture_classes(foo_fixture_table_names)
        setup_fixture_accessors(foo_fixture_table_names)
      end
    end
  end

  private

  def load_fixtures
    foo_fixture_path = self.class.foo_fixture_path
    foo_fixture_table_names = self.class.foo_fixture_table_names
    class_names = self.class.foo_fixture_classes.each_with_object({}) do |klass, memo|
      memo[klass.table_name.to_sym] = klass if klass.table_name.present? && foo_fixture_table_names.include?(klass.table_name)
    end
    foo_fixtures = ActiveRecord::Fixtures.create_fixtures(foo_fixture_path, foo_fixture_table_names, class_names) do
      Foo::Base.connection
    end

    super.merge(Hash[foo_fixtures.map { |f| [f.name, f] }])
  end
end

class ActiveSupport::TestCase
  extend FooFixtures::ClassMethods
  prepend FooFixtures

  self.foo_fixture_classes.each do |fixture_class|
    set_fixture_class fixture_class.table_name.to_sym => fixture_class
  end

  ...
end