FIX: Ensure only one line is around the annotation (#669)

Author: xrav3nz

lib/annotate/annotate_models.rb

@@ -540,9 +540,9 @@ def annotate_one_file(file_name, info_block, position, options = {})
         new_content = if %w(after bottom).include?(options[position].to_s)
                         magic_comments_block + (old_content.rstrip + "\n\n" + wrapped_info_block)
                       elsif magic_comments_block.empty?
-                        magic_comments_block + wrapped_info_block + "\n" + old_content
+                        magic_comments_block + wrapped_info_block + "\n" + old_content.lstrip
                       else
-                        magic_comments_block + "\n" + wrapped_info_block + "\n" + old_content
+                        magic_comments_block + "\n" + wrapped_info_block + "\n" + old_content.lstrip
                       end
       else
         # replace the old annotation with the new one

spec/lib/annotate/annotate_models_spec.rb

@@ -1803,6 +1803,18 @@ class User < ActiveRecord::Base
       end
     end
 
+    it 'only keeps a single empty line around the annotation (position :before)' do
+      content = "class User < ActiveRecord::Base\nend\n"
+      magic_comments_list_each do |magic_comment|
+        schema_info = AnnotateModels.get_schema_info(@klass, '== Schema Info')
+        model_file_name, = write_model 'user.rb', "#{magic_comment}\n\n\n\n#{content}"
+
+        annotate_one_file position: :before
+
+        expect(File.read(model_file_name)).to eq("#{magic_comment}\n\n#{schema_info}\n#{content}")
+      end
+    end
+
     it 'does not change whitespace between magic comments and model file content (position :after)' do
       content = "class User < ActiveRecord::Base\nend\n"
       magic_comments_list_each do |magic_comment|