From baf1e60451ddf04bbe57915f309e380c0963384b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Catuhe?= <francois@hey.com>
Date: Wed, 25 Feb 2026 10:11:16 +0100
Subject: [PATCH] Set engine layout on ApplicationController
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Without an explicit layout declaration, Litestream::ApplicationController
inherits the layout from its base_controller_class. When the base controller
declares its own layout (e.g. `layout "admin"`), Litestream renders
inside the host app's layout, which breaks because main app route helpers
are not available inside mounted engine views (NameError).

This matches what other Rails engine dashboards do:
- mission_control-jobs: `layout "mission_control/jobs/application"`
- audits1984: `layout "audits1984/application"`
- blazer: `layout "blazer/application"`

The litestream/application layout already exists — it just was never
declared on the controller.
---
 app/controllers/litestream/application_controller.rb    | 2 ++
 test/controllers/test_processes_controller.rb           | 1 +
 test/dummy/app/controllers/my_application_controller.rb | 1 +
 test/litestream/test_base_application_controller.rb     | 4 ++++
 4 files changed, 8 insertions(+)

diff --git a/app/controllers/litestream/application_controller.rb b/app/controllers/litestream/application_controller.rb
index b3f0582..9813e56 100644
--- a/app/controllers/litestream/application_controller.rb
+++ b/app/controllers/litestream/application_controller.rb
@@ -1,5 +1,7 @@
 module Litestream
   class ApplicationController < Litestream.base_controller_class.constantize
+    layout "litestream/application"
+
     protect_from_forgery with: :exception
 
     if Litestream.password
diff --git a/test/controllers/test_processes_controller.rb b/test/controllers/test_processes_controller.rb
index 3f15a6e..80432f1 100644
--- a/test/controllers/test_processes_controller.rb
+++ b/test/controllers/test_processes_controller.rb
@@ -21,6 +21,7 @@ class Litestream::TestProcessesController < ActionDispatch::IntegrationTest
       Litestream.stub :databases, stubbed_databases do
         get litestream.process_url
         assert_response :success
+        assert_select "title", "Litestream"
 
         assert_select "#process_12345", 1 do
           assert_select "small", "sleeping"
diff --git a/test/dummy/app/controllers/my_application_controller.rb b/test/dummy/app/controllers/my_application_controller.rb
index 2aa9205..9195d2f 100644
--- a/test/dummy/app/controllers/my_application_controller.rb
+++ b/test/dummy/app/controllers/my_application_controller.rb
@@ -1,2 +1,3 @@
 class MyApplicationController < ApplicationController
+  layout "application"
 end
diff --git a/test/litestream/test_base_application_controller.rb b/test/litestream/test_base_application_controller.rb
index d7e2e10..32df1f3 100644
--- a/test/litestream/test_base_application_controller.rb
+++ b/test/litestream/test_base_application_controller.rb
@@ -8,4 +8,8 @@ class Litestream::BaseApplicationControllerTest < ActiveSupport::TestCase
   test "engine's ApplicationController inherits from configured base_controller_class" do
     assert Litestream::ApplicationController < MyApplicationController
   end
+
+  test "engine's ApplicationController uses its own layout regardless of base controller layout" do
+    assert_equal "litestream/application", Litestream::ApplicationController._layout
+  end
 end