Apply manual rubocop fixes

spec/policies/code_ocean/file_policy_spec.rb

@@ -3,86 +3,86 @@
 require 'rails_helper'
 
 describe CodeOcean::FilePolicy do
-  subject { described_class }
+  subject(:policy) { described_class }
 
   let(:exercise) { FactoryBot.create(:fibonacci) }
   let(:submission) { FactoryBot.create(:submission) }
 
   permissions :create? do
-    context 'as part of an exercise' do
+    context 'when being part of an exercise' do
       let(:file) { exercise.files.first }
 
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryBot.build(:admin), file)
+        expect(policy).to permit(FactoryBot.build(:admin), file)
       end
 
       it 'grants access to authors' do
-        expect(subject).to permit(exercise.author, file)
+        expect(policy).to permit(exercise.author, file)
       end
 
       it 'does not grant access to all other users' do
         %i[external_user teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
+          expect(policy).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end
 
-    context 'as part of a submission' do
+    context 'when being part of a submission' do
       let(:file) { submission.files.first }
 
-      context 'where file creation is allowed' do
+      context 'when file creation is allowed' do
         before do
           submission.exercise.update(allow_file_creation: true)
         end
 
         it 'grants access to authors' do
-          expect(subject).to permit(submission.author, file)
+          expect(policy).to permit(submission.author, file)
         end
       end
 
-      context 'where file creation is not allowed' do
+      context 'when file creation is not allowed' do
         before do
           submission.exercise.update(allow_file_creation: false)
         end
 
         it 'grants access to authors' do
-          expect(subject).not_to permit(submission.author, file)
+          expect(policy).not_to permit(submission.author, file)
         end
       end
 
       it 'does not grant access to all other users' do
         %i[admin external_user teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
+          expect(policy).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end
   end
 
   permissions :destroy? do
-    context 'as part of an exercise' do
+    context 'when being part of an exercise' do
       let(:file) { exercise.files.first }
 
       it 'grants access to admins' do
-        expect(subject).to permit(FactoryBot.build(:admin), file)
+        expect(policy).to permit(FactoryBot.build(:admin), file)
       end
 
       it 'grants access to authors' do
-        expect(subject).to permit(exercise.author, file)
+        expect(policy).to permit(exercise.author, file)
       end
 
       it 'does not grant access to all other users' do
         %i[external_user teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
+          expect(policy).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end
 
-    context 'as part of a submission' do
+    context 'when being part of a submission' do
       let(:file) { submission.files.first }
 
       it 'does not grant access to anyone' do
         %i[admin external_user teacher].each do |factory_name|
-          expect(subject).not_to permit(FactoryBot.build(factory_name), file)
+          expect(policy).not_to permit(FactoryBot.build(factory_name), file)
         end
       end
     end