NoMethodError：未定義のメソッド `validates_confirmation_of 'Sinatra

Question

上記のエラーが表示されていますが、理由を理解できません。ここでは、スタックトレースです：

/Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/app/models/user.rb:8:in `<class:User>': undefined method `validates_confirmation_of' for User:Class (NoMethodError) 
     from /Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/app/models/user.rb:4:in `<top (required)>' 
     from /Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/app/data_mapper_setup.rb:6:in `require_relative' 
     from /Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/app/data_mapper_setup.rb:6:in `<top (required)>' 
     from /Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/app/app.rb:4:in `require_relative' 
     from /Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/app/app.rb:4:in `<top (required)>' 
     from /Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/spec/spec_helper.rb:3:in `require' 
     from /Users/benrumble/Desktop/Apple_tv_movies_and_stuff/skeletons/Full_Stack_Sinatra_App_Skeleton/Skeleton_App_with_user_login:sign_up_and_bcrypt/spec/spec_helper.rb:3:in `<top (required)>' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration.rb:1394:in `require' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration.rb:1394:in `block in requires=' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration.rb:1394:in `each' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration.rb:1394:in `requires=' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration_options.rb:112:in `block in process_options_into' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration_options.rb:111:in `each' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration_options.rb:111:in `process_options_into' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/configuration_options.rb:21:in `configure' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/runner.rb:99:in `setup' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/runner.rb:86:in `run' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/runner.rb:71:in `run' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/lib/rspec/core/runner.rb:45:in `invoke' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/gems/rspec-core-3.5.0/exe/rspec:4:in `<top (required)>' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/bin/rspec:23:in `load' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/bin/rspec:23:in `<main>' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval' 
     from /Users/benrumble/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `<main>' 

、ここで私はと「DM-検証」なしで試してみましたuser.rbモデル

require 'bcrypt' 
require 'dm-validations' 

class User 
    attr_reader :password 
    attr_accessor :password_confirmation 

    validates_confirmation_of :password 

    include DataMapper::Resource 

    property :id, Serial 
    property :email, String 

    property :password_digest, String, length: 60 

    def password=(password) 
    @password = password 
    self.password_digest = BCrypt::Password.create(password) 
    end 

end 

ですが、それは違いを作るdoesntの。

助けがあれば助かります。

おかげ

Answer 1

私はクラスを宣言した後の最初の行として

include DataMapper::Resource 

ラインを移動することで、この問題を解決しました。