ruby-on-rails - Rails 枚举验证不起作用但引发 ArgumentError

Question

创建了一个线程 here ，但这并不能解决我的问题。

我的代码是:

course.rb

class Course < ApplicationRecord
  COURSE_TYPES = %i( trial limited unlimited )
  enum course_type: COURSE_TYPES
  validates_inclusion_of :course_type, in: COURSE_TYPES
end

course_controller.rb

class CoursesController < ApiController
  def create
    course = Course.new(course_params) # <-- Exception here
    if course.save # <-- But I expect the process can go here
      render json: course, status: :ok
    else
      render json: {error: 'Failed to create course'}, status: :unprocessable_entity
    end
  end

  private    
    def course_params
      params.require(:course).permit(:course_type)
    end
end

我的测试用例:

course_controller_spec.rb

describe '#create' do
  context 'when invalid course type' do
    let(:params) { { course_type: 'english' } }
    before { post :create, params: { course: params } }

    it 'returns 422' do
      expect(response.status).to eq(422)
    end
  end
end

运行上述测试用例时，我得到了 ArgumentError Rails issues 中描述的异常

所以我希望如果我设置一个无效的 course_type枚举，它将 在验证阶段失败而不是引发异常 .

此外，我知道在 here 的 rails 钩子(Hook)下到底发生了什么。而我 不想手动抢救在每个分配枚举类型值的代码块中都会出现这种异常!

对此有何建议？

Answer 1

我找到了解决方案。我自己在 Rails 6 中测试过。

# app/models/contact.rb
class Contact < ApplicationRecord
  include LiberalEnum

  enum kind: {
    phone: 'phone', skype: 'skype', whatsapp: 'whatsapp'
  }

  liberal_enum :kind

  validates :kind, presence: true, inclusion: { in: kinds.values }
end

# app/models/concerns/liberal_enum.rb
module LiberalEnum
  extend ActiveSupport::Concern

  class_methods do
    def liberal_enum(attribute)
      decorate_attribute_type(attribute, :enum) do |subtype|
        LiberalEnumType.new(attribute, public_send(attribute.to_s.pluralize), subtype)
      end
    end
  end
end

# app/types/liberal_enum_type.rb
class LiberalEnumType < ActiveRecord::Enum::EnumType
  # suppress <ArgumentError>
  # returns a value to be able to use +inclusion+ validation
  def assert_valid_value(value)
    value
  end
end

用法:

contact = Contact.new(kind: 'foo')
contact.valid? #=> false
contact.errors.full_messages #=> ["Kind is not included in the list"]