BulkImports: Better error message when import fails

Improve the message bubbled up from backend when an import fails due to
validations

app/models/bulk_imports/entity.rb

@@ -118,8 +118,8 @@ class BulkImports::Entity < ApplicationRecord
 
     if source.self_and_descendants.any? { |namespace| namespace.full_path == destination_namespace }
       errors.add(
-        :destination_namespace,
-        s_('BulkImport|destination group cannot be part of the source group tree')
+        :base,
+        s_('BulkImport|Import failed: Destination cannot be a subgroup of the source group. Change the destination and try again.')
       )
     end
   end

changelogs/unreleased/kassio-bulkimports-better-destination-validation-error-message.yml

+---
+title: Better error message when import fails due to backend validation
+merge_request: 54827
+author:
+type: changed

locale/gitlab.pot

@@ -5095,6 +5095,9 @@ msgstr ""
 msgid "BulkImport|From source group"
 msgstr ""
 
+msgid "BulkImport|Import failed: Destination cannot be a subgroup of the source group. Change the destination and try again."
+msgstr ""
+
 msgid "BulkImport|Import groups from GitLab"
 msgstr ""
 
@@ -5122,9 +5125,6 @@ msgstr ""
 msgid "BulkImport|You have no groups to import"
 msgstr ""
 
-msgid "BulkImport|destination group cannot be part of the source group tree"
-msgstr ""
-
 msgid "BulkImport|expected an associated Group but has an associated Project"
 msgstr ""
 

spec/models/bulk_imports/entity_spec.rb

@@ -103,7 +103,9 @@ RSpec.describe BulkImports::Entity, type: :model do
         )
 
         expect(entity).not_to be_valid
-        expect(entity.errors).to include(:destination_namespace)
+        expect(entity.errors).to include(:base)
+        expect(entity.errors[:base])
+          .to include('Import failed: Destination cannot be a subgroup of the source group. Change the destination and try again.')
       end
 
       it 'is invalid if destination namespace is a descendant of the source' do
@@ -118,7 +120,8 @@ RSpec.describe BulkImports::Entity, type: :model do
         )
 
         expect(entity).not_to be_valid
-        expect(entity.errors).to include(:destination_namespace)
+        expect(entity.errors[:base])
+          .to include('Import failed: Destination cannot be a subgroup of the source group. Change the destination and try again.')
       end
     end
   end