Upgrade Rails to version 5.2.1 and adopt code & specs where necessary

Signed-off-by: Sebastian Serth <Sebastian.Serth@student.hpi.de>

app/models/anomaly_notification.rb

@@ -1,4 +1,4 @@
-class AnomalyNotification < ActiveRecord::Base
+class AnomalyNotification < ApplicationRecord
   belongs_to :user, polymorphic: true
   belongs_to :exercise
   belongs_to :exercise_collection

app/models/application_record.rb

@@ -0,0 +1,3 @@
+class ApplicationRecord < ActiveRecord::Base
+  self.abstract_class = true
+end

app/models/code_harbor_link.rb

@@ -1,4 +1,4 @@
-class CodeHarborLink < ActiveRecord::Base
+class CodeHarborLink < ApplicationRecord
   validates :oauth2token, presence: true
   validates :user_id, presence: true
 

app/models/code_ocean/file.rb

@@ -15,7 +15,7 @@ module CodeOcean
     end
   end
 
-  class File < ActiveRecord::Base
+  class File < ApplicationRecord
     include DefaultValues
 
     DEFAULT_WEIGHT = 1.0
@@ -28,12 +28,11 @@ module CodeOcean
     before_validation :set_ancestor_values, if: :incomplete_descendent?
 
     belongs_to :context, polymorphic: true
-    belongs_to :execution_environment
-    belongs_to :file
+    belongs_to :file, class_name: 'CodeOcean::File', optional: true # This is only required for submissions and is validated below
     alias_method :ancestor, :file
     belongs_to :file_type
 
-    has_many :files
+    has_many :files, class_name: 'CodeOcean::File'
     has_many :testruns
     has_many :comments
     alias_method :descendants, :files
@@ -59,6 +58,7 @@ module CodeOcean
     validates :role, inclusion: {in: ROLES}
     validates :weight, if: :teacher_defined_test?, numericality: true, presence: true
     validates :weight, absence: true, unless: :teacher_defined_test?
+    validates :file, presence: true if :context.is_a?(Submission)
 
     validates_with FileNameValidator, fields: [:name, :path, :file_type_id]
 

app/models/comment.rb

@@ -1,4 +1,4 @@
-class Comment < ActiveRecord::Base
+class Comment < ApplicationRecord
   # inherit the creation module: encapsulates that this is a polymorphic user, offers some aliases and makes sure that all necessary attributes are set.
   include Creation
   attr_accessor :username, :date, :updated, :editable

app/models/consumer.rb

@@ -1,4 +1,4 @@
-class Consumer < ActiveRecord::Base
+class Consumer < ApplicationRecord
   has_many :users
 
   scope :with_users, -> { where('id IN (SELECT consumer_id FROM internal_users)') }

app/models/error.rb

@@ -1,4 +1,4 @@
-class Error < ActiveRecord::Base
+class Error < ApplicationRecord
   belongs_to :execution_environment
 
   scope :for_execution_environment, ->(execution_environment) { where(execution_environment_id: execution_environment.id) }

app/models/error_template.rb

@@ -1,4 +1,4 @@
-class ErrorTemplate < ActiveRecord::Base
+class ErrorTemplate < ApplicationRecord
   belongs_to :execution_environment
   has_and_belongs_to_many :error_template_attributes
 

app/models/error_template_attribute.rb

@@ -1,4 +1,4 @@
-class ErrorTemplateAttribute < ActiveRecord::Base
+class ErrorTemplateAttribute < ApplicationRecord
   has_and_belongs_to_many :error_template
 
   def to_s

app/models/event.rb

@@ -1,7 +1,7 @@
-class Event < ActiveRecord::Base
+class Event < ApplicationRecord
   belongs_to :user, polymorphic: true
   belongs_to :exercise
-  belongs_to :file
+  belongs_to :file, class_name: 'CodeOcean::File'
 
   validates :category, presence: true
   validates :data, presence: true

app/models/execution_environment.rb

@@ -1,6 +1,6 @@
 require File.expand_path('../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
 
-class ExecutionEnvironment < ActiveRecord::Base
+class ExecutionEnvironment < ApplicationRecord
   include Creation
   include DefaultValues
 

app/models/exercise.rb

@@ -1,7 +1,7 @@
 require 'nokogiri'
 require File.expand_path('../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
 
-class Exercise < ActiveRecord::Base
+class Exercise < ApplicationRecord
   include Context
   include Creation
   include DefaultValues
@@ -23,8 +23,8 @@ class Exercise < ActiveRecord::Base
   accepts_nested_attributes_for :exercise_tags
   has_many :user_exercise_feedbacks
 
-  has_many :external_users, source: :user, source_type: ExternalUser, through: :submissions
-  has_many :internal_users, source: :user, source_type: InternalUser, through: :submissions
+  has_many :external_users, source: :user, source_type: 'ExternalUser', through: :submissions
+  has_many :internal_users, source: :user, source_type: 'InternalUser', through: :submissions
   alias_method :users, :external_users
 
   scope :with_submissions, -> { where('id IN (SELECT exercise_id FROM submissions)') }

app/models/exercise_collection.rb

@@ -1,4 +1,4 @@
-class ExerciseCollection < ActiveRecord::Base
+class ExerciseCollection < ApplicationRecord
   include TimeHelper
 
   has_many :exercise_collection_items, dependent: :delete_all

app/models/exercise_collection_item.rb

@@ -1,4 +1,4 @@
-class ExerciseCollectionItem < ActiveRecord::Base
+class ExerciseCollectionItem < ApplicationRecord
   belongs_to :exercise_collection
   belongs_to :exercise
 end

app/models/exercise_tag.rb

@@ -1,4 +1,4 @@
-class ExerciseTag < ActiveRecord::Base
+class ExerciseTag < ApplicationRecord
 
   belongs_to :tag
   belongs_to :exercise

app/models/external_user.rb

@@ -1,4 +1,4 @@
-class ExternalUser < ActiveRecord::Base
+class ExternalUser < ApplicationRecord
   include User
 
   validates :consumer_id, presence: true

app/models/file_template.rb

@@ -1,4 +1,4 @@
-class FileTemplate < ActiveRecord::Base
+class FileTemplate < ApplicationRecord
 
   belongs_to :file_type
 

app/models/file_type.rb

@@ -1,6 +1,6 @@
 require File.expand_path('../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
 
-class FileType < ActiveRecord::Base
+class FileType < ApplicationRecord
   include Creation
   include DefaultValues
 
@@ -11,7 +11,7 @@ class FileType < ActiveRecord::Base
   after_initialize :set_default_values
 
   has_many :execution_environments
-  has_many :files
+  has_many :files, class_name: 'CodeOcean::File'
   has_many :file_templates
 
   validates :binary, boolean_presence: true

app/models/hint.rb

@@ -1,4 +1,4 @@
-class Hint < ActiveRecord::Base
+class Hint < ApplicationRecord
   belongs_to :execution_environment
 
   validates :execution_environment_id, presence: true

app/models/internal_user.rb

@@ -1,4 +1,4 @@
-class InternalUser < ActiveRecord::Base
+class InternalUser < ApplicationRecord
   include User
 
   authenticates_with_sorcery!

app/models/intervention.rb

@@ -1,7 +1,7 @@
-class Intervention < ActiveRecord::Base
+class Intervention < ApplicationRecord
 
   has_many :user_exercise_interventions
-  has_many :users, through: :user_exercise_interventions, source_type: "ExternalUser"
+  has_many :users, through: :user_exercise_interventions, source_type: 'ExternalUser'
 
   def to_s
     name

app/models/lti_parameter.rb

@@ -1,4 +1,4 @@
-class LtiParameter < ActiveRecord::Base
+class LtiParameter < ApplicationRecord
   belongs_to :consumer, foreign_key: "consumers_id"
   belongs_to :exercise, foreign_key: "exercises_id"
   belongs_to :external_user, foreign_key: "external_users_id"

app/models/proxy_exercise.rb

@@ -1,4 +1,4 @@
-class ProxyExercise < ActiveRecord::Base
+class ProxyExercise < ApplicationRecord
 
     after_initialize :generate_token
     after_initialize :set_reason

app/models/remote_evaluation_mapping.rb

@@ -1,5 +1,5 @@
 # todo: reference to lti_param_model
-class RemoteEvaluationMapping < ActiveRecord::Base
+class RemoteEvaluationMapping < ApplicationRecord
   before_create :generate_token, unless: :validation_token?
   belongs_to :exercise
   belongs_to :user

app/models/request_for_comment.rb

@@ -1,4 +1,4 @@
-class RequestForComment < ActiveRecord::Base
+class RequestForComment < ApplicationRecord
   include Creation
   belongs_to :submission
   belongs_to :exercise

app/models/search.rb

@@ -1,4 +1,4 @@
-class Search < ActiveRecord::Base
+class Search < ApplicationRecord
   belongs_to :user, polymorphic: true
   belongs_to :exercise
 end

app/models/structured_error.rb

@@ -1,7 +1,6 @@
-class StructuredError < ActiveRecord::Base
+class StructuredError < ApplicationRecord
   belongs_to :error_template
   belongs_to :submission
-  belongs_to :file, class_name: 'CodeOcean::File'
 
   has_many :structured_error_attributes
 

app/models/structured_error_attribute.rb

@@ -1,4 +1,4 @@
-class StructuredErrorAttribute < ActiveRecord::Base
+class StructuredErrorAttribute < ApplicationRecord
   belongs_to :structured_error
   belongs_to :error_template_attribute
 

app/models/submission.rb

@@ -1,4 +1,4 @@
-class Submission < ActiveRecord::Base
+class Submission < ApplicationRecord
   include Context
   include Creation
 

app/models/subscription.rb

@@ -1,4 +1,4 @@
-class Subscription < ActiveRecord::Base
+class Subscription < ApplicationRecord
   belongs_to :user, polymorphic: true
   belongs_to :request_for_comment
 end

app/models/tag.rb

@@ -1,4 +1,4 @@
-class Tag < ActiveRecord::Base
+class Tag < ApplicationRecord
 
   has_many :exercise_tags
   has_many :exercises, through: :exercise_tags

app/models/testrun.rb

@@ -1,4 +1,4 @@
-class Testrun < ActiveRecord::Base
+class Testrun < ApplicationRecord
     belongs_to :file, class_name: 'CodeOcean::File'
     belongs_to :submission
 end

app/models/user_exercise_feedback.rb

@@ -1,4 +1,4 @@
-class UserExerciseFeedback < ActiveRecord::Base
+class UserExerciseFeedback < ApplicationRecord
   include Creation
 
   belongs_to :exercise

app/models/user_exercise_intervention.rb

@@ -1,4 +1,4 @@
-class UserExerciseIntervention < ActiveRecord::Base
+class UserExerciseIntervention < ApplicationRecord
 
   belongs_to :user, polymorphic: true
   belongs_to :intervention

app/models/user_proxy_exercise_exercise.rb

@@ -1,4 +1,4 @@
-class UserProxyExerciseExercise < ActiveRecord::Base
+class UserProxyExerciseExercise < ApplicationRecord
 
   belongs_to :user, polymorphic: true
   belongs_to :exercise