Show snippet error update to the user

app/services/snippets/update_service.rb

@@ -52,7 +52,7 @@ module Snippets
           create_commit(snippet) if snippet.repository_exists?
         end
       rescue => e
-        snippet.errors.add(:repository, 'Error updating the snippet')
+        snippet.errors.add(:repository, e.message)
         log_error(e.message)
 
         false

changelogs/unreleased/fj-show-error-message-snippet-update.yml

+---
+title: Show snippet error update to the user
+merge_request: 28516
+author:
+type: changed

spec/features/projects/snippets/user_updates_snippet_spec.rb

@@ -54,9 +54,11 @@ describe 'Projects > Snippets > User updates a snippet', :js do
   end
 
   context 'when the git operation fails' do
+    let(:error_message) { 'foobar' }
+
     before do
       allow_next_instance_of(Snippets::UpdateService) do |instance|
-        allow(instance).to receive(:create_commit).and_raise(StandardError)
+        allow(instance).to receive(:create_commit).and_raise(StandardError, error_message)
       end
 
       fill_in('project_snippet_title', with: 'Snippet new title')
@@ -65,7 +67,7 @@ describe 'Projects > Snippets > User updates a snippet', :js do
     end
 
     it 'renders edit page and displays the error' do
-      expect(page.find('.flash-container span').text).to eq('Error updating the snippet')
+      expect(page.find('.flash-container span').text).to eq(error_message)
       expect(page).to have_content('Edit Snippet')
     end
   end

spec/features/snippets/user_edits_snippet_spec.rb

@@ -85,9 +85,11 @@ describe 'User edits snippet', :js do
   end
 
   context 'when the git operation fails' do
+    let(:error_message) { 'foobar' }
+
     before do
       allow_next_instance_of(Snippets::UpdateService) do |instance|
-        allow(instance).to receive(:create_commit).and_raise(StandardError)
+        allow(instance).to receive(:create_commit).and_raise(StandardError, error_message)
       end
 
       fill_in 'personal_snippet_title', with: 'New Snippet Title'
@@ -96,7 +98,7 @@ describe 'User edits snippet', :js do
     end
 
     it 'renders edit page and displays the error' do
-      expect(page.find('.flash-container span').text).to eq('Error updating the snippet')
+      expect(page.find('.flash-container span').text).to eq(error_message)
       expect(page).to have_content('Edit Snippet')
     end
   end

spec/services/snippets/update_service_spec.rb

@@ -141,14 +141,16 @@ describe Snippets::UpdateService do
       end
 
       it 'returns error when the commit action fails' do
+        error_message = 'foobar'
+
         allow_next_instance_of(SnippetRepository) do |instance|
-          allow(instance).to receive(:multi_files_action).and_raise(SnippetRepository::CommitError)
+          allow(instance).to receive(:multi_files_action).and_raise(SnippetRepository::CommitError, error_message)
         end
 
         response = subject
 
         expect(response).to be_error
-        expect(response.payload[:snippet].errors.full_messages).to eq ['Repository Error updating the snippet']
+        expect(response.payload[:snippet].errors[:repository].to_sentence).to eq error_message
       end
     end
 
@@ -168,12 +170,14 @@ describe Snippets::UpdateService do
       end
 
       context 'when an error is raised' do
+        let(:error_message) { 'foobar' }
+
         before do
-          allow(snippet.snippet_repository).to receive(:multi_files_action).and_raise(SnippetRepository::CommitError, 'foobar')
+          allow(snippet.snippet_repository).to receive(:multi_files_action).and_raise(SnippetRepository::CommitError, error_message)
         end
 
         it 'logs the error' do
-          expect(Gitlab::AppLogger).to receive(:error).with('foobar')
+          expect(Gitlab::AppLogger).to receive(:error).with(error_message)
 
           subject
         end
@@ -182,7 +186,7 @@ describe Snippets::UpdateService do
           response = subject
 
           expect(response).to be_error
-          expect(response.payload[:snippet].errors.full_messages).to eq ['Repository Error updating the snippet']
+          expect(response.payload[:snippet].errors[:repository].to_sentence).to eq error_message
         end
       end