Merge branch 'bvl-rename-all-reserved-paths' into 'master'

Rename all forbidden paths again

Closes #32625

See merge request !11713

changelogs/unreleased/bvl-rename-all-reserved-paths.yml

+---
+title: Rename all reserved paths that could have been created
+merge_request: 11713
+author:

db/post_migrate/20170525140254_rename_all_reserved_paths_again.rb

+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class RenameAllReservedPathsAgain < ActiveRecord::Migration
+  include Gitlab::Database::RenameReservedPathsMigration::V1
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  TOP_LEVEL_ROUTES = %w[
+      -
+      .well-known
+      abuse_reports
+      admin
+      all
+      api
+      assets
+      autocomplete
+      ci
+      dashboard
+      explore
+      files
+      groups
+      health_check
+      help
+      hooks
+      import
+      invites
+      issues
+      jwt
+      koding
+      member
+      merge_requests
+      new
+      notes
+      notification_settings
+      oauth
+      profile
+      projects
+      public
+      repository
+      robots.txt
+      s
+      search
+      sent_notifications
+      services
+      snippets
+      teams
+      u
+      unicorn_test
+      unsubscribes
+      uploads
+      users
+  ].freeze
+
+  PROJECT_WILDCARD_ROUTES = %w[
+      badges
+      blame
+      blob
+      builds
+      commits
+      create
+      create_dir
+      edit
+      environments/folders
+      files
+      find_file
+      gitlab-lfs/objects
+      info/lfs/objects
+      new
+      preview
+      raw
+      refs
+      tree
+      update
+      wikis
+    ].freeze
+
+  GROUP_ROUTES = %w[
+      activity
+      analytics
+      audit_events
+      avatar
+      edit
+      group_members
+      hooks
+      issues
+      labels
+      ldap
+      ldap_group_links
+      merge_requests
+      milestones
+      notification_setting
+      pipeline_quota
+      projects
+      subgroups
+  ].freeze
+
+  def up
+    disable_statement_timeout
+
+    TOP_LEVEL_ROUTES.each { |route| rename_root_paths(route) }
+    PROJECT_WILDCARD_ROUTES.each { |route| rename_wildcard_paths(route) }
+    GROUP_ROUTES.each { |route| rename_child_paths(route) }
+  end
+
+  def down
+    disable_statement_timeout
+
+    revert_renames
+  end
+end

lib/gitlab/database/rename_reserved_paths_migration/v1.rb

@@ -29,6 +29,11 @@ module Gitlab
           paths = Array(paths)
           RenameNamespaces.new(paths, self).rename_namespaces(type: :top_level)
         end
+
+        def revert_renames
+          RenameProjects.new([], self).revert_renames
+          RenameNamespaces.new([], self).revert_renames
+        end
       end
     end
   end

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

@@ -6,7 +6,10 @@ module Gitlab
           attr_reader :paths, :migration
 
           delegate :update_column_in_batches,
+                   :execute,
                    :replace_sql,
+                   :quote_string,
+                   :say,
                    to: :migration
 
           def initialize(paths, migration)
@@ -26,24 +29,45 @@ module Gitlab
             new_path = rename_path(namespace_path, old_path)
             new_full_path = join_routable_path(namespace_path, new_path)
 
+            perform_rename(routable, old_full_path, new_full_path)
+
+            [old_full_path, new_full_path]
+          end
+
+          def perform_rename(routable, old_full_path, new_full_path)
             # skips callbacks & validations
+            new_path = new_full_path.split('/').last
             routable.class.where(id: routable)
               .update_all(path: new_path)
 
             rename_routes(old_full_path, new_full_path)
-
-            [old_full_path, new_full_path]
           end
 
           def rename_routes(old_full_path, new_full_path)
+            routes = Route.arel_table
+
+            quoted_old_full_path = quote_string(old_full_path)
+            quoted_old_wildcard_path = quote_string("#{old_full_path}/%")
+
+            filter = if Database.mysql?
+                       "lower(routes.path) = lower('#{quoted_old_full_path}') "\
+                       "OR routes.path LIKE '#{quoted_old_wildcard_path}'"
+                     else
+                       "routes.id IN "\
+                       "( SELECT routes.id FROM routes WHERE lower(routes.path) = lower('#{quoted_old_full_path}') "\
+                       "UNION SELECT routes.id FROM routes WHERE routes.path ILIKE '#{quoted_old_wildcard_path}' )"
+                     end
+
             replace_statement = replace_sql(Route.arel_table[:path],
                                             old_full_path,
                                             new_full_path)
 
-            update_column_in_batches(:routes, :path, replace_statement)  do |table, query|
-              path_or_children = table[:path].matches_any([old_full_path, "#{old_full_path}/%"])
-              query.where(path_or_children)
-            end
+            update = Arel::UpdateManager.new(ActiveRecord::Base)
+                       .table(routes)
+                       .set([[routes[:path], replace_statement]])
+                       .where(Arel::Nodes::SqlLiteral.new(filter))
+
+            execute(update.to_sql)
           end
 
           def rename_path(namespace_path, path_was)
@@ -86,33 +110,75 @@ module Gitlab
 
           def move_folders(directory, old_relative_path, new_relative_path)
             old_path = File.join(directory, old_relative_path)
-            return unless File.directory?(old_path)
+            unless File.directory?(old_path)
+              say "#{old_path} doesn't exist, skipping"
+              return
+            end
 
             new_path = File.join(directory, new_relative_path)
             FileUtils.mv(old_path, new_path)
           end
 
           def remove_cached_html_for_projects(project_ids)
+            project_ids.each do |project_id|
               update_column_in_batches(:projects, :description_html, nil) do |table, query|
-              query.where(table[:id].in(project_ids))
+                query.where(table[:id].eq(project_id))
               end
 
               update_column_in_batches(:issues, :description_html, nil) do |table, query|
-              query.where(table[:project_id].in(project_ids))
+                query.where(table[:project_id].eq(project_id))
               end
 
               update_column_in_batches(:merge_requests, :description_html, nil) do |table, query|
-              query.where(table[:target_project_id].in(project_ids))
+                query.where(table[:target_project_id].eq(project_id))
               end
 
               update_column_in_batches(:notes, :note_html, nil) do |table, query|
-              query.where(table[:project_id].in(project_ids))
+                query.where(table[:project_id].eq(project_id))
               end
 
               update_column_in_batches(:milestones, :description_html, nil) do |table, query|
-              query.where(table[:project_id].in(project_ids))
+                query.where(table[:project_id].eq(project_id))
               end
             end
+          end
+
+          def track_rename(type, old_path, new_path)
+            key = redis_key_for_type(type)
+            Gitlab::Redis.with do |redis|
+              redis.lpush(key, [old_path, new_path].to_json)
+              redis.expire(key, 2.weeks.to_i)
+            end
+            say "tracked rename: #{key}: #{old_path} -> #{new_path}"
+          end
+
+          def reverts_for_type(type)
+            key = redis_key_for_type(type)
+
+            Gitlab::Redis.with do |redis|
+              failed_reverts = []
+
+              while rename_info = redis.lpop(key)
+                path_before_rename, path_after_rename = JSON.parse(rename_info)
+                say "renaming #{type} from #{path_after_rename} back to #{path_before_rename}"
+                begin
+                  yield(path_before_rename, path_after_rename)
+                rescue StandardError => e
+                  failed_reverts << rename_info
+                  say "Renaming #{type} from #{path_after_rename} back to "\
+                      "#{path_before_rename} failed. Review the error and try "\
+                      "again by running the `down` action. \n"\
+                      "#{e.message}: \n #{e.backtrace.join("\n")}"
+                end
+              end
+
+              failed_reverts.each { |rename_info| redis.lpush(key, rename_info) }
+            end
+          end
+
+          def redis_key_for_type(type)
+            "rename:#{migration.name}:#{type}"
+          end
 
           def file_storage?
             CarrierWave::Uploader::Base.storage == CarrierWave::Storage::File

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

@@ -26,6 +26,12 @@ module Gitlab
           def rename_namespace(namespace)
             old_full_path, new_full_path = rename_path_for_routable(namespace)
 
+            track_rename('namespace', old_full_path, new_full_path)
+
+            rename_namespace_dependencies(namespace, old_full_path, new_full_path)
+          end
+
+          def rename_namespace_dependencies(namespace, old_full_path, new_full_path)
             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)
@@ -33,6 +39,23 @@ module Gitlab
             remove_cached_html_for_projects(projects_for_namespace(namespace).map(&:id))
           end
 
+          def revert_renames
+            reverts_for_type('namespace') do |path_before_rename, current_path|
+              matches_path = MigrationClasses::Route.arel_table[:path].matches(current_path)
+              namespace = MigrationClasses::Namespace.joins(:route)
+                            .where(matches_path).first&.becomes(MigrationClasses::Namespace)
+
+              if namespace
+                perform_rename(namespace, current_path, path_before_rename)
+
+                rename_namespace_dependencies(namespace, current_path, path_before_rename)
+              else
+                say "Couldn't rename namespace from #{current_path} back to #{path_before_rename}, "\
+                    "namespace was renamed, or no longer exists at the expected path"
+              end
+            end
+          end
+
           def rename_user(old_username, new_username)
             MigrationClasses::User.where(username: old_username)
               .update_all(username: new_username)

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

@@ -16,12 +16,37 @@ module Gitlab
           def rename_project(project)
             old_full_path, new_full_path = rename_path_for_routable(project)
 
+            track_rename('project', old_full_path, new_full_path)
+
+            move_project_folders(project, old_full_path, new_full_path)
+          end
+
+          def move_project_folders(project, old_full_path, new_full_path)
             move_repository(project, old_full_path, new_full_path)
             move_repository(project, "#{old_full_path}.wiki", "#{new_full_path}.wiki")
             move_uploads(old_full_path, new_full_path)
             move_pages(old_full_path, new_full_path)
           end
 
+          def revert_renames
+            reverts_for_type('project') do |path_before_rename, current_path|
+              matches_path = MigrationClasses::Route.arel_table[:path].matches(current_path)
+              project = MigrationClasses::Project.joins(:route)
+                          .where(matches_path).first
+
+              if project
+                perform_rename(project, current_path, path_before_rename)
+
+                move_project_folders(project, current_path, path_before_rename)
+              else
+                say "Couldn't rename project from #{current_path} back to "\
+                    "#{path_before_rename}, project was renamed or no longer "\
+                    "exists at the expected path."
+
+              end
+            end
+          end
+
           def move_repository(project, old_path, new_path)
             unless gitlab_shell.mv_repository(project.repository_storage_path,
                                               old_path,

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

@@ -6,6 +6,7 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameBase, :trunca
 
   before do
     allow(migration).to receive(:say)
+    TestEnv.clean_test_path
   end
 
   def migration_namespace(namespace)
@@ -153,6 +154,30 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameBase, :trunca
     end
   end
 
+  describe '#perform_rename' do
+    describe 'for namespaces' do
+      let(:namespace) { create(:namespace, path: 'the-path') }
+      it 'renames the path' do
+        subject.perform_rename(migration_namespace(namespace), 'the-path', 'renamed')
+
+        expect(namespace.reload.path).to eq('renamed')
+      end
+
+      it 'renames all the routes for the namespace' do
+        child = create(:group, path: 'child', parent: namespace)
+        project = create(:project, namespace: child, path: 'the-project')
+        other_one = create(:namespace, path: 'the-path-is-similar')
+
+        subject.perform_rename(migration_namespace(namespace), 'the-path', 'renamed')
+
+        expect(namespace.reload.route.path).to eq('renamed')
+        expect(child.reload.route.path).to eq('renamed/child')
+        expect(project.reload.route.path).to eq('renamed/child/the-project')
+        expect(other_one.reload.route.path).to eq('the-path-is-similar')
+      end
+    end
+  end
+
   describe '#move_pages' do
     it 'moves the pages directory' do
       expect(subject).to receive(:move_folders)
@@ -203,4 +228,53 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameBase, :trunca
       expect(File.exist?(expected_file)).to be(true)
     end
   end
+
+  describe '#track_rename', redis: true do
+    it 'tracks a rename in redis' do
+      key = 'rename:FakeRenameReservedPathMigrationV1:namespace'
+
+      subject.track_rename('namespace', 'path/to/namespace', 'path/to/renamed')
+
+      old_path, new_path = [nil, nil]
+      Gitlab::Redis.with do |redis|
+        rename_info = redis.lpop(key)
+        old_path, new_path = JSON.parse(rename_info)
+      end
+
+      expect(old_path).to eq('path/to/namespace')
+      expect(new_path).to eq('path/to/renamed')
+    end
+  end
+
+  describe '#reverts_for_type', redis: true do
+    it 'yields for each tracked rename' do
+      subject.track_rename('project', 'old_path', 'new_path')
+      subject.track_rename('project', 'old_path2', 'new_path2')
+      subject.track_rename('namespace', 'namespace_path', 'new_namespace_path')
+
+      expect { |b| subject.reverts_for_type('project', &b) }
+        .to yield_successive_args(%w(old_path2 new_path2), %w(old_path new_path))
+      expect { |b| subject.reverts_for_type('namespace', &b) }
+        .to yield_with_args('namespace_path', 'new_namespace_path')
+    end
+
+    it 'keeps the revert in redis if it failed' do
+      subject.track_rename('project', 'old_path', 'new_path')
+
+      subject.reverts_for_type('project') do
+        raise 'whatever happens, keep going!'
+      end
+
+      key = 'rename:FakeRenameReservedPathMigrationV1:project'
+      stored_renames = nil
+      rename_count = 0
+      Gitlab::Redis.with do |redis|
+        stored_renames = redis.lrange(key, 0, 1)
+        rename_count = redis.llen(key)
+      end
+
+      expect(rename_count).to eq(1)
+      expect(JSON.parse(stored_renames.first)).to eq(%w(old_path new_path))
+    end
+  end
 end

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

@@ -3,9 +3,11 @@ require 'spec_helper'
 describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces, :truncate do
   let(:migration) { FakeRenameReservedPathMigrationV1.new }
   let(:subject) { described_class.new(['the-path'], migration) }
+  let(:namespace) { create(:group, name: 'the-path') }
 
   before do
     allow(migration).to receive(:say)
+    TestEnv.clean_test_path
   end
 
   def migration_namespace(namespace)
@@ -137,8 +139,6 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces, :
   end
 
   describe "#rename_namespace" do
-    let(:namespace) { create(:group, name: 'the-path') }
-
     it 'renames paths & routes for the namespace' do
       expect(subject).to receive(:rename_path_for_routable)
                            .with(namespace)
@@ -149,11 +149,27 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces, :
       expect(namespace.reload.path).to eq('the-path0')
     end
 
+    it 'tracks the rename' do
+      expect(subject).to receive(:track_rename)
+                           .with('namespace', 'the-path', 'the-path0')
+
+      subject.rename_namespace(namespace)
+    end
+
+    it 'renames things related to the namespace' do
+      expect(subject).to receive(:rename_namespace_dependencies)
+                           .with(namespace, 'the-path', 'the-path0')
+
+      subject.rename_namespace(namespace)
+    end
+  end
+
+  describe '#rename_namespace_dependencies' do
     it "moves the the repository for a project in the namespace" do
       create(:project, namespace: namespace, path: "the-path-project")
       expected_repo = File.join(TestEnv.repos_path, "the-path0", "the-path-project.git")
 
-      subject.rename_namespace(namespace)
+      subject.rename_namespace_dependencies(namespace, 'the-path', 'the-path0')
 
       expect(File.directory?(expected_repo)).to be(true)
     end
@@ -161,13 +177,13 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces, :
     it "moves the uploads for the namespace" do
       expect(subject).to receive(:move_uploads).with("the-path", "the-path0")
 
-      subject.rename_namespace(namespace)
+      subject.rename_namespace_dependencies(namespace, 'the-path', 'the-path0')
     end
 
     it "moves the pages for the namespace" do
       expect(subject).to receive(:move_pages).with("the-path", "the-path0")
 
-      subject.rename_namespace(namespace)
+      subject.rename_namespace_dependencies(namespace, 'the-path', 'the-path0')
     end
 
     it 'invalidates the markdown cache of related projects' do
@@ -175,13 +191,13 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces, :
 
       expect(subject).to receive(:remove_cached_html_for_projects).with([project.id])
 
-      subject.rename_namespace(namespace)
+      subject.rename_namespace_dependencies(namespace, 'the-path', 'the-path0')
     end
 
     it "doesn't rename users for other namespaces" do
       expect(subject).not_to receive(:rename_user)
 
-      subject.rename_namespace(namespace)
+      subject.rename_namespace_dependencies(namespace, 'the-path', 'the-path0')
     end
 
     it 'renames the username of a namespace for a user' do
@@ -189,7 +205,7 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces, :
 
       expect(subject).to receive(:rename_user).with('the-path', 'the-path0')
 
-      subject.rename_namespace(user.namespace)
+      subject.rename_namespace_dependencies(user.namespace, 'the-path', 'the-path0')
     end
   end
 
@@ -224,4 +240,50 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameNamespaces, :
       subject.rename_namespaces(type: :child)
     end
   end
+
+  describe '#revert_renames', redis: true do
+    it 'renames the routes back to the previous values' do
+      project = create(:project, path: 'a-project', namespace: namespace)
+      subject.rename_namespace(namespace)
+
+      expect(subject).to receive(:perform_rename)
+                           .with(
+                             kind_of(Gitlab::Database::RenameReservedPathsMigration::V1::MigrationClasses::Namespace),
+                             'the-path0',
+                             'the-path'
+                           ).and_call_original
+
+      subject.revert_renames
+
+      expect(namespace.reload.path).to eq('the-path')
+      expect(namespace.reload.route.path).to eq('the-path')
+      expect(project.reload.route.path).to eq('the-path/a-project')
+    end
+
+    it 'moves the repositories back to their original place' do
+      project = create(:project, path: 'a-project', namespace: namespace)
+      project.create_repository
+      subject.rename_namespace(namespace)
+
+      expected_path = File.join(TestEnv.repos_path, 'the-path', 'a-project.git')
+
+      expect(subject).to receive(:rename_namespace_dependencies)
+                           .with(
+                             kind_of(Gitlab::Database::RenameReservedPathsMigration::V1::MigrationClasses::Namespace),
+                             'the-path0',
+                             'the-path'
+                           ).and_call_original
+
+      subject.revert_renames
+
+      expect(File.directory?(expected_path)).to be_truthy
+    end
+
+    it "doesn't break when the namespace was renamed" do
+      subject.rename_namespace(namespace)
+      namespace.update_attributes!(path: 'renamed-afterwards')
+
+      expect { subject.revert_renames }.not_to raise_error
+    end
+  end
 end

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

@@ -3,9 +3,15 @@ require 'spec_helper'
 describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameProjects, :truncate do
   let(:migration) { FakeRenameReservedPathMigrationV1.new }
   let(:subject) { described_class.new(['the-path'], migration) }
+  let(:project) do
+    create(:empty_project,
+           path: 'the-path',
+           namespace: create(:namespace, path: 'known-parent' ))
+  end
 
   before do
     allow(migration).to receive(:say)
+    TestEnv.clean_test_path
   end
 
   describe '#projects_for_paths' do
@@ -47,12 +53,6 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameProjects, :tr
   end
 
   describe '#rename_project' do
-    let(:project) do
-      create(:empty_project,
-             path: 'the-path',
-             namespace: create(:namespace, path: 'known-parent' ))
-    end
-
     it 'renames path & route for the project' do
       expect(subject).to receive(:rename_path_for_routable)
                            .with(project)
@@ -63,27 +63,42 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameProjects, :tr
       expect(project.reload.path).to eq('the-path0')
     end
 
+    it 'tracks the rename' do
+      expect(subject).to receive(:track_rename)
+                           .with('project', 'known-parent/the-path', 'known-parent/the-path0')
+
+      subject.rename_project(project)
+    end
+
+    it 'renames the folders for the project' do
+      expect(subject).to receive(:move_project_folders).with(project, 'known-parent/the-path', 'known-parent/the-path0')
+
+      subject.rename_project(project)
+    end
+  end
+
+  describe '#move_project_folders' do
     it 'moves the wiki & the repo' do
       expect(subject).to receive(:move_repository)
                            .with(project, 'known-parent/the-path.wiki', 'known-parent/the-path0.wiki')
       expect(subject).to receive(:move_repository)
                            .with(project, 'known-parent/the-path', 'known-parent/the-path0')
 
-      subject.rename_project(project)
+      subject.move_project_folders(project, 'known-parent/the-path', 'known-parent/the-path0')
     end
 
     it 'moves uploads' do
       expect(subject).to receive(:move_uploads)
                            .with('known-parent/the-path', 'known-parent/the-path0')
 
-      subject.rename_project(project)
+      subject.move_project_folders(project, 'known-parent/the-path', 'known-parent/the-path0')
     end
 
     it 'moves pages' do
       expect(subject).to receive(:move_pages)
                            .with('known-parent/the-path', 'known-parent/the-path0')
 
-      subject.rename_project(project)
+      subject.move_project_folders(project, 'known-parent/the-path', 'known-parent/the-path0')
     end
   end
 
@@ -99,4 +114,47 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1::RenameProjects, :tr
       expect(File.directory?(expected_path)).to be(true)
     end
   end
+
+  describe '#revert_renames', redis: true do
+    it 'renames the routes back to the previous values' do
+      subject.rename_project(project)
+
+      expect(subject).to receive(:perform_rename)
+                           .with(
+                             kind_of(Gitlab::Database::RenameReservedPathsMigration::V1::MigrationClasses::Project),
+                             'known-parent/the-path0',
+                             'known-parent/the-path'
+                           ).and_call_original
+
+      subject.revert_renames
+
+      expect(project.reload.path).to eq('the-path')
+      expect(project.route.path).to eq('known-parent/the-path')
+    end
+
+    it 'moves the repositories back to their original place' do
+      project.create_repository
+      subject.rename_project(project)
+
+      expected_path = File.join(TestEnv.repos_path, 'known-parent', 'the-path.git')
+
+      expect(subject).to receive(:move_project_folders)
+                           .with(
+                             kind_of(Gitlab::Database::RenameReservedPathsMigration::V1::MigrationClasses::Project),
+                             'known-parent/the-path0',
+                             'known-parent/the-path'
+                           ).and_call_original
+
+      subject.revert_renames
+
+      expect(File.directory?(expected_path)).to be_truthy
+    end
+
+    it "doesn't break when the project was renamed" do
+      subject.rename_project(project)
+      project.update_attributes!(path: 'renamed-afterwards')
+
+      expect { subject.revert_renames }.not_to raise_error
+    end
+  end
 end

spec/lib/gitlab/database/rename_reserved_paths_migration/v1_spec.rb

@@ -51,4 +51,26 @@ describe Gitlab::Database::RenameReservedPathsMigration::V1, :truncate do
       subject.rename_root_paths('the-path')
     end
   end
+
+  describe '#revert_renames' do
+    it 'renames namespaces' do
+      rename_namespaces = double
+      expect(described_class::RenameNamespaces)
+        .to receive(:new).with([], subject)
+              .and_return(rename_namespaces)
+      expect(rename_namespaces).to receive(:revert_renames)
+
+      subject.revert_renames
+    end
+
+    it 'renames projects' do
+      rename_projects = double
+      expect(described_class::RenameProjects)
+        .to receive(:new).with([], subject)
+              .and_return(rename_projects)
+      expect(rename_projects).to receive(:revert_renames)
+
+      subject.revert_renames
+    end
+  end
 end

spec/support/fake_migration_classes.rb

 class FakeRenameReservedPathMigrationV1 < ActiveRecord::Migration
   include Gitlab::Database::RenameReservedPathsMigration::V1
+
+  def version
+    '20170316163845'
+  end
+
+  def name
+    "FakeRenameReservedPathMigrationV1"
+  end
 end