Replace manual activerecord translations with helpers

app/models/execution_environment.rb

@@ -76,9 +76,7 @@ class ExecutionEnvironment < ApplicationRecord
 
   def valid_test_setup?
     if test_command? ^ testing_framework?
-      errors.add(:test_command,
-        I18n.t('activerecord.errors.messages.together',
-          attribute: I18n.t('activerecord.attributes.execution_environment.testing_framework')))
+      errors.add(:test_command, :together, attribute: ExecutionEnvironment.human_attribute_name('testing_framework'))
     end
   end
 

app/models/exercise.rb

@@ -566,8 +566,7 @@ class Exercise < ApplicationRecord
 
   def valid_main_file?
     if files.count(&:main_file?) > 1
-      errors.add(:files,
-        I18n.t('activerecord.errors.models.exercise.at_most_one_main_file'))
+      errors.add(:files, :at_most_one_main_file)
     end
   end
   private :valid_main_file?
@@ -577,15 +576,13 @@ class Exercise < ApplicationRecord
 
     valid = true
     if late_submission_deadline.present? && submission_deadline.blank?
-      errors.add(:late_submission_deadline,
-        I18n.t('activerecord.errors.models.exercise.late_submission_deadline_not_alone'))
+      errors.add(:late_submission_deadline, :not_alone)
       valid = false
     end
 
     if submission_deadline.present? && late_submission_deadline.present? &&
        late_submission_deadline < submission_deadline
-      errors.add(:late_submission_deadline,
-        I18n.t('activerecord.errors.models.exercise.late_submission_deadline_not_before_submission_deadline'))
+      errors.add(:late_submission_deadline, :not_before_submission_deadline)
       valid = false
     end
 

app/models/exercise_collection.rb

@@ -30,7 +30,7 @@ working_time: time_to_f(item.exercise.average_working_time)}
   end
 
   def to_s
-    "#{I18n.t('activerecord.models.exercise_collection.one')}: #{name} (#{id})"
+    "#{ExerciseCollection.model_name.human}: #{name} (#{id})"
   end
 
   def self.ransackable_attributes(_auth_object = nil)

app/models/exercise_tip.rb

@@ -16,9 +16,7 @@ class ExerciseTip < ApplicationRecord
     unless ExerciseTip.exists?(
       exercise:, id: parent_exercise_tip
     )
-      errors.add :parent_exercise_tip,
-        I18n.t('activerecord.errors.messages.together',
-          attribute: I18n.t('activerecord.attributes.exercise_tip.tip'))
+      errors.add :parent_exercise_tip, :together, attribute: ExerciseTip.human_attribute_name('tip')
     end
   end
 end

app/models/tip.rb

@@ -13,16 +13,15 @@ class Tip < ApplicationRecord
     unless [
       description?, example?
     ].include?(true)
-      errors.add :description,
-        I18n.t('activerecord.errors.messages.at_least', attribute: I18n.t('activerecord.attributes.tip.example'))
+      errors.add :description, :at_least, attribute: Tip.human_attribute_name('example')
     end
   end
 
   def to_s
     if title?
-      "#{I18n.t('activerecord.models.tip.one')}: #{title} (#{id})"
+      "#{Tip.model_name.human}: #{title} (#{id})"
     else
-      "#{I18n.t('activerecord.models.tip.one')} #{id}"
+      "#{Tip.model_name.human} #{id}"
     end
   end