Cache Highlighted Diff Lines when reload MR content20034-highlighted-diff-cached

3 files changed, 13 insertions, 1 deletions

diff --git a/app/helpers/diff_helper.rb b/app/helpers/diff_helper.rb
index 75b029365f9..b2af1294fe6 100644
--- a/app/helpers/diff_helper.rb
+++ b/app/helpers/diff_helper.rb
@@ -30,7 +30,8 @@ module DiffHelper
       options[:paths] = params.values_at(:old_path, :new_path)
     end
 
-    Commit.max_diff_options.merge(options)
+    # Select truthy values those are the ones that makes a change
+    Commit.max_diff_options.merge(options).select { |_, v| v }
   end
 
   def safe_diff_files(diffs, diff_refs: nil, repository: nil)
diff --git a/app/models/merge_request.rb b/app/models/merge_request.rb
index daee7289c32..dfd93c6de10 100644
--- a/app/models/merge_request.rb
+++ b/app/models/merge_request.rb
@@ -342,6 +342,8 @@ class MergeRequest < ActiveRecord::Base
 
     merge_request_diff.reload_content
 
+    MergeRequests::MergeRequestDiffCacheService.new.execute(merge_request)
+
     new_diff_refs = self.diff_refs
 
     update_diff_notes_positions(
diff --git a/app/services/merge_requests/merge_request_diff_cache_service.rb b/app/services/merge_requests/merge_request_diff_cache_service.rb
new file mode 100644
index 00000000000..e8e4cd13cd1
--- /dev/null
+++ b/app/services/merge_requests/merge_request_diff_cache_service.rb
@@ -0,0 +1,9 @@
+module MergeRequests
+  class MergeRequestDiffCacheService
+    def execute(merge_request)
+      # REVIEW how do we share default options here and in the controllers
+      # We store by calculating the cache
+      merge_request.highlighted_safe_diff_files(Commit.max_diff_options)
+    end
+  end
+end