extracted boolean validation logic into stand-alone validator

app/models/code_ocean/file.rb

@@ -1,4 +1,5 @@
 require File.expand_path('../../../uploaders/file_uploader', __FILE__)
+require File.expand_path('../../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
 
 module CodeOcean
   class File < ActiveRecord::Base
@@ -35,9 +36,9 @@ module CodeOcean
     validates :feedback_message, absence: true, unless: :teacher_defined_test?
     validates :file_type_id, presence: true
     validates :hashed_content, if: :content_present?, presence: true
-    validates :hidden, inclusion: {in: [true, false]}
+    validates :hidden, boolean_presence: true
     validates :name, presence: true
-    validates :read_only, inclusion: {in: [true, false]}
+    validates :read_only, boolean_presence: true
     validates :role, inclusion: {in: ROLES}
     validates :weight, if: :teacher_defined_test?, numericality: true, presence: true
     validates :weight, absence: true, unless: :teacher_defined_test?

app/models/execution_environment.rb

@@ -1,3 +1,5 @@
+require File.expand_path('../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
+
 class ExecutionEnvironment < ActiveRecord::Base
   include Creation
   include DefaultValues
@@ -16,7 +18,7 @@ class ExecutionEnvironment < ActiveRecord::Base
   validate :working_docker_image?, if: :validate_docker_image?
   validates :docker_image, presence: true
   validates :memory_limit, numericality: {greater_than_or_equal_to: DockerClient::MINIMUM_MEMORY_LIMIT, only_integer: true}, presence: true
-  validates :network_enabled, inclusion: {in: [true, false]}
+  validates :network_enabled, boolean_presence: true
   validates :name, presence: true
   validates :permitted_execution_time, numericality: {only_integer: true}, presence: true
   validates :pool_size, numericality: {only_integer: true}, presence: true

app/models/exercise.rb

@@ -1,3 +1,5 @@
+require File.expand_path('../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
+
 class Exercise < ActiveRecord::Base
   include Context
   include Creation
@@ -16,7 +18,7 @@ class Exercise < ActiveRecord::Base
   validate :valid_main_file?
   validates :description, presence: true
   validates :execution_environment_id, presence: true
-  validates :public, inclusion: {in: [true, false]}
+  validates :public, boolean_presence: true
   validates :title, presence: true
   validates :token, presence: true, uniqueness: true
 

app/models/file_type.rb

@@ -1,3 +1,5 @@
+require File.expand_path('../../../lib/active_model/validations/boolean_presence_validator', __FILE__)
+
 class FileType < ActiveRecord::Base
   include Creation
   include DefaultValues
@@ -11,12 +13,12 @@ class FileType < ActiveRecord::Base
   has_many :execution_environments
   has_many :files
 
-  validates :binary, inclusion: {in: [true, false]}
+  validates :binary, boolean_presence: true
   validates :editor_mode, presence: true, unless: :binary?
-  validates :executable, inclusion: {in: [true, false]}
+  validates :executable, boolean_presence: true
   validates :indent_size, presence: true, unless: :binary?
   validates :name, presence: true
-  validates :renderable, inclusion: {in: [true, false]}
+  validates :renderable, boolean_presence: true
 
   [:audio, :image, :video].each do |type|
     define_method("#{type}?") do

lib/active_model/validations/boolean_presence_validator.rb

@@ -0,0 +1,12 @@
+module ActiveModel
+  module Validations
+    class BooleanPresenceValidator < EachValidator
+      def validate(record)
+        [attributes].flatten.each do |attribute|
+          value = record.send(:read_attribute_for_validation, attribute)
+          record.errors.add(attribute, nil, options) unless [false, true].include?(value)
+        end
+      end
+    end
+  end
+end

spec/models/code_ocean/file_spec.rb

@@ -9,6 +9,8 @@ describe CodeOcean::File do
 
   it 'validates the presence of the hidden flag' do
     expect(file.errors[:hidden]).to be_present
+    file.update(hidden: false)
+    expect(file.errors[:hidden]).to be_blank
   end
 
   it 'validates the presence of a name' do
@@ -17,6 +19,8 @@ describe CodeOcean::File do
 
   it 'validates the presence of the read-only flag' do
     expect(file.errors[:read_only]).to be_present
+    file.update(read_only: false)
+    expect(file.errors[:read_only]).to be_blank
   end
 
   context 'as a teacher-defined test' do

spec/models/execution_environment_spec.rb

@@ -34,6 +34,8 @@ describe ExecutionEnvironment do
 
   it 'validates the presence of the network enabled flag' do
     expect(execution_environment.errors[:network_enabled]).to be_present
+    execution_environment.update(network_enabled: false)
+    expect(execution_environment.errors[:network_enabled]).to be_blank
   end
 
   it 'validates the numericality of the permitted run time' do

spec/models/exercise_spec.rb

@@ -28,6 +28,8 @@ describe Exercise do
 
   it 'validates the presence of the public flag' do
     expect(exercise.errors[:public]).to be_present
+    exercise.update(public: false)
+    expect(exercise.errors[:public]).to be_blank
   end
 
   it 'validates the presence of a title' do

spec/models/file_type_spec.rb

@@ -5,6 +5,8 @@ describe FileType do
 
   it 'validates the presence of the binary flag' do
     expect(file_type.errors[:binary]).to be_present
+    file_type.update(binary: false)
+    expect(file_type.errors[:binary]).to be_blank
   end
 
   context 'when binary' do
@@ -33,6 +35,8 @@ describe FileType do
 
   it 'validates the presence of the executable flag' do
     expect(file_type.errors[:executable]).to be_present
+    file_type.update(executable: false)
+    expect(file_type.errors[:executable]).to be_blank
   end
 
   it 'validates the presence of a name' do
@@ -41,6 +45,8 @@ describe FileType do
 
   it 'validates the presence of the renderable flag' do
     expect(file_type.errors[:renderable]).to be_present
+    file_type.update(renderable: false)
+    expect(file_type.errors[:renderable]).to be_blank
   end
 
   it 'validates the presence of a user' do