Fix importer for GitHub comments on diff

Fix comments on diff after LegacyDiffNote was extracted from Note

CHANGELOG

@@ -45,6 +45,7 @@ v 8.8.4 (unreleased)
   - Fix todos page throwing errors when you have a project pending deletion
   - Reduce number of SQL queries when rendering user references
   - Upgrade to jQuery 2
+  - Fix importer for GitHub comments on diff
 
 v 8.8.3
   - Fix 404 page when viewing TODOs that contain milestones or labels in different projects. !4312

lib/gitlab/github_import/comment_formatter.rb

@@ -8,6 +8,7 @@ module Gitlab
           commit_id: raw_data.commit_id,
           line_code: line_code,
           author_id: author_id,
+          type: type,
           created_at: raw_data.created_at,
           updated_at: raw_data.updated_at
         }
@@ -53,6 +54,10 @@ module Gitlab
       def note
         formatter.author_line(author) + body
       end
+
+      def type
+        'LegacyDiffNote' if on_diff?
+      end
     end
   end
 end

spec/lib/gitlab/github_import/comment_formatter_spec.rb

@@ -29,6 +29,7 @@ describe Gitlab::GithubImport::CommentFormatter, lib: true do
           commit_id: nil,
           line_code: nil,
           author_id: project.creator_id,
+          type: nil,
           created_at: created_at,
           updated_at: updated_at
         }
@@ -56,6 +57,7 @@ describe Gitlab::GithubImport::CommentFormatter, lib: true do
           commit_id: '6dcb09b5b57875f334f61aebed695e2e4193db5e',
           line_code: 'ce1be0ff4065a6e9415095c95f25f47a633cef2b_4_3',
           author_id: project.creator_id,
+          type: 'LegacyDiffNote',
           created_at: created_at,
           updated_at: updated_at
         }