Avoid updating snippet content when not present

app/services/snippets/update_service.rb

@@ -38,7 +38,8 @@ module Snippets
       # Once we can perform different operations through this service
       # we won't need to keep track of the `content` and `file_name` fields
       if snippet_files.any?
-        params.merge!(content: snippet_files[0].content, file_name: snippet_files[0].file_path)
+        params[:content] = snippet_files[0].content if snippet_files[0].content
+        params[:file_name] = snippet_files[0].file_path
       end
 
       snippet.assign_attributes(params)

changelogs/unreleased/fj-avoid-updating-snippet-content-when-not-present.yml

+---
+title: Avoid updating snippet content when snippet_files content is not present
+merge_request: 34865
+author:
+type: fixed

spec/services/snippets/update_service_spec.rb

@@ -349,6 +349,18 @@ describe Snippets::UpdateService do
         end
       end
 
+      context 'when snippet_file content is not present' do
+        let(:snippet_files) { [{ action: :move, previous_path: file_path, file_path: 'new_file_path' }] }
+
+        it 'does not update snippet content' do
+          content = snippet.content
+
+          expect(subject).to be_success
+
+          expect(snippet.reload.content).to eq content
+        end
+      end
+
       context 'when snippet_files param is invalid' do
         let(:snippet_files) { [{ action: 'invalid_action' }] }