Add additional test case for new CodeOcean::File#read method

app/models/code_ocean/file.rb

@@ -58,7 +58,7 @@ module CodeOcean
 
     def read
       if native_file?
-        valid = Pathname(native_file.current_path).fnmatch? ::File.join(native_file.root, '**')
+        valid = Pathname(native_file.current_path).realpath.fnmatch? ::File.join(native_file.root, '**')
         return nil unless valid
 
         native_file.read

spec/models/code_ocean/file_spec.rb

@@ -69,7 +69,26 @@ describe CodeOcean::File do
     end
 
     context 'when the path has been modified' do
-      before { file.update(native_file: '../../../../secrets.yml') }
+      before do
+        file.update_column(:native_file, '../../../../secrets.yml') # rubocop:disable Rails/SkipsModelValidations
+        file.reload
+      end
+
+      it 'does not read the native file' do
+        expect(file.read).not_to be_present
+      end
+    end
+
+    context 'when a symlink is used' do
+      let(:fake_upload_location) { File.join(CarrierWave::Uploader::Base.new.root, 'uploads', 'files', 'secrets.yml') }
+
+      before do
+        File.symlink Rails.root.join('config/secrets.yml'), fake_upload_location
+        file.update_column(:native_file, '../secrets.yml') # rubocop:disable Rails/SkipsModelValidations
+        file.reload
+      end
+
+      after { File.delete(fake_upload_location) }
 
       it 'does not read the native file' do
         expect(file.read).not_to be_present