Update username when renaming a user-namespace

lib/gitlab/database/rename_reserved_paths_migration/v1/migration_classes.rb

@@ -48,6 +48,14 @@ module Gitlab
             def self.name
               'Namespace'
             end
+
+            def kind
+              type == 'Group' ? 'group' : 'user'
+            end
+          end
+
+          class User < ActiveRecord::Base
+            self.table_name = 'users'
           end
           class Route < ActiveRecord::Base

lib/gitlab/database/rename_reserved_paths_migration/v1/rename_namespaces.rb

@@ -29,9 +29,15 @@ module Gitlab
             move_repositories(namespace, old_full_path, new_full_path)
             move_uploads(old_full_path, new_full_path)
             move_pages(old_full_path, new_full_path)
+            rename_user(old_full_path, new_full_path) if namespace.kind == 'user'
             remove_cached_html_for_projects(projects_for_namespace(namespace).map(&:id))
           end
+          def rename_user(old_username, new_username)
+            MigrationClasses::User.where(username: old_username)
+              .update_all(username: new_username)
+          end
+
           def move_repositories(namespace, old_full_path, new_full_path)
             repo_paths_for_namespace(namespace).each do |repository_storage_path|
               # Ensure old directory exists before moving it

spec/lib/gitlab/database/rename_reserved_paths_migration/v1/rename_namespaces_spec.rb

@@ -137,7 +137,7 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces do
   end
   describe "#rename_namespace" do
-    let(:namespace) { create(:namespace, path: 'the-path') }
+    let(:namespace) { create(:group, name: 'the-path') }
     it 'renames paths & routes for the namespace' do
       expect(subject).to receive(:rename_path_for_routable).
@@ -177,6 +177,31 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces do
       subject.rename_namespace(namespace)
     end
+
+    it "doesn't rename users for other namespaces" do
+      expect(subject).not_to receive(:rename_user)
+
+      subject.rename_namespace(namespace)
+    end
+
+    it 'renames the username of a namespace for a user' do
+      user = create(:user, username: 'the-path')
+
+      expect(subject).to receive(:rename_user).with('the-path', 'the-path0')
+
+      subject.rename_namespace(user.namespace)
+    end
+  end
+
+  describe '#rename_user' do
+    it 'renames a username' do
+      subject = described_class.new([], migration)
+      user = create(:user, username: 'broken')
+
+      subject.rename_user('broken', 'broken0')
+
+      expect(user.reload.username).to eq('broken0')
+    end
   end
   describe '#rename_namespaces' do