Add line type conditional to diff line helper

app/assets/stylesheets/pages/diff.scss

@@ -67,15 +67,19 @@
         line-height: $code_line_height;
         font-size: $code_font_size;
 
-        &.noteable_line.old:before {
+        &.noteable_line.old {
+          &:before {
             content: '-';
             position: absolute;
           }
+        }
 
-        &.noteable_line.new:before {
+        &.noteable_line.new {
+          &:before {
             content: '+';
             position: absolute;
           }
+        }
 
         span {
           white-space: pre;

app/helpers/diff_helper.rb

@@ -40,11 +40,13 @@ module DiffHelper
     (unfold) ? 'unfold js-unfold' : ''
   end
 
-  def diff_line_content(line)
+  def diff_line_content(line, line_type = nil)
     if line.blank?
       "  ".html_safe
     else
-      line[0] = ''
+      if line_type == 'new' || line_type == 'old'
+        line[0] = " "
+      end
       line
     end
   end

app/views/projects/diffs/_line.html.haml

@@ -23,4 +23,4 @@
         = link_text
       - else
         = link_to "", "##{line_code}", id: line_code, data: { linenumber: link_text }
-    %td.line_content{class: "noteable_line #{type} #{line_code}", data: { line_code: line_code }}= diff_line_content(line.text)
+    %td.line_content{class: "noteable_line #{type} #{line_code}", data: { line_code: line_code }}= diff_line_content(line.text, type)

app/views/projects/notes/discussions/_diff.html.haml

@@ -22,7 +22,7 @@
             - else
               %td.old_line.diff-line-num{data: {linenumber: raw(type == "new" ? " " : line.old_pos)}}
               %td.new_line.diff-line-num{data: {linenumber: raw(type == "old" ? " " : line.new_pos)}}
-              %td.line_content{class: "noteable_line #{type} #{line_code}", line_code: line_code}= diff_line_content(line.text)
+              %td.line_content{class: "noteable_line #{type} #{line_code}", line_code: line_code}= diff_line_content(line.text, type)
 
               - if line_code == note.line_code
                 = render "projects/notes/diff_notes_with_reply", notes: discussion_notes