Fixes support for generators as well as manifest and install tasks when working in a Rails engine.

lib/generators/stimulus/stimulus_generator.rb

@@ -6,17 +6,22 @@ class StimulusGenerator < Rails::Generators::NamedBase # :nodoc:
   class_option :skip_manifest, type: :boolean, default: false, desc: "Don't update the stimulus manifest"
 
   def copy_view_files
-    @attribute = stimulus_attribute_value(controller_name)
-    template "controller.js", "app/javascript/controllers/#{controller_name}_controller.js"
+    @attribute = stimulus_attribute_value(File.join(class_path, file_name))
+    template "controller.js", File.join("app/javascript/controllers", class_path, "#{file_name}_controller.js")
     rails_command "stimulus:manifest:update" unless Rails.root.join("config/importmap.rb").exist? || options[:skip_manifest]
   end
 
   private
-    def controller_name
-      name.underscore.gsub(/_controller$/, "")
+
+    def file_name
+      @_file_name ||= remove_possible_suffix(super)
+    end
+
+    def remove_possible_suffix(name)
+      name.sub(/_?controller$/i, "")
     end
 
     def stimulus_attribute_value(controller_name)
-      controller_name.gsub(/\//, "--").gsub("_", "-")
+      controller_name.sub(/\A\/+/, "").sub(/\/+\z/, "").gsub(/\//, "--").gsub("_", "-")
     end
 end

lib/install/stimulus_with_bun.rb

@@ -1,18 +1,19 @@
-say "Create controllers directory"
-empty_directory "app/javascript/controllers"
-copy_file "#{__dir__}/app/javascript/controllers/index_for_node.js",
-  "app/javascript/controllers/index.js"
-copy_file "#{__dir__}/app/javascript/controllers/application.js",
-  "app/javascript/controllers/application.js"
-copy_file "#{__dir__}/app/javascript/controllers/hello_controller.js",
-  "app/javascript/controllers/hello_controller.js"
+say "Installing Stimulus (for bun) into #{destination_root}"
+inside destination_root do
+  say "Create controllers directory"
+  empty_directory "app/javascript/controllers"
+  copy_file "#{__dir__}/app/javascript/controllers/application.js", "app/javascript/controllers/application.js"
+  run "rails generate stimulus hello --without-manifest"
+  run "rails stimulus:manifest:update"
 
-if (Rails.root.join("app/javascript/application.js")).exist?
-  say "Import Stimulus controllers"
-  append_to_file "app/javascript/application.js", %(import "./controllers"\n)
-else
-  say %(Couldn't find "app/javascript/application.js".\nYou must import "./controllers" in your JavaScript entrypoint file), :red
-end
+  if File.exist?("app/javascript/application.js")
+    say "Import Stimulus controllers"
+    append_to_file "app/javascript/application.js", %(import "./controllers"\n)
+  else
+    say %(Couldn't find "app/javascript/application.js".), :red
+    say %(You must import "./controllers" in your JavaScript entrypoint file), :red
+  end
 
-say "Install Stimulus"
-run "bun add @hotwired/stimulus"
+  say "Install Stimulus"
+  run "bun add @hotwired/stimulus"
+end

lib/install/stimulus_with_importmap.rb

@@ -1,22 +1,27 @@
-say "Create controllers directory"
-empty_directory "app/javascript/controllers"
-copy_file "#{__dir__}/app/javascript/controllers/index_for_importmap.js",
-  "app/javascript/controllers/index.js"
-copy_file "#{__dir__}/app/javascript/controllers/application.js",
-  "app/javascript/controllers/application.js"
-copy_file "#{__dir__}/app/javascript/controllers/hello_controller.js",
-  "app/javascript/controllers/hello_controller.js"
+say "Installing Stimulus (for importmap-rails) into #{destination_root}"
+inside destination_root do
+  say "Create controllers directory"
+  empty_directory "app/javascript/controllers"
+  copy_file "#{__dir__}/app/javascript/controllers/index_for_importmap.js", "app/javascript/controllers/index.js"
+  copy_file "#{__dir__}/app/javascript/controllers/application.js", "app/javascript/controllers/application.js"
+  run "rails generate stimulus hello --without-manifest"
 
-say "Import Stimulus controllers"
-append_to_file "app/javascript/application.js", %(import "controllers"\n)
+  if File.exist?("app/javascript/application.js")
+    say "Import Stimulus controllers"
+    append_to_file "app/javascript/application.js", %(import "controllers"\n)
+  else
+    say %(Couldn't find "app/javascript/application.js".), :red
+    say %(You must import "controllers" in your JavaScript entrypoint file), :red
+  end
 
-say "Pin Stimulus"
-say %(Appending: pin "@hotwired/stimulus", to: "stimulus.min.js")
-append_to_file "config/importmap.rb", %(pin "@hotwired/stimulus", to: "stimulus.min.js"\n)
+  say "Pin Stimulus"
+  say %(Appending: pin "@hotwired/stimulus", to: "stimulus.min.js")
+  append_to_file "config/importmap.rb", %(pin "@hotwired/stimulus", to: "stimulus.min.js"\n)
 
-say %(Appending: pin "@hotwired/stimulus-loading", to: "stimulus-loading.js")
-append_to_file "config/importmap.rb", %(pin "@hotwired/stimulus-loading", to: "stimulus-loading.js"\n)
+  say %(Appending: pin "@hotwired/stimulus-loading", to: "stimulus-loading.js")
+  append_to_file "config/importmap.rb", %(pin "@hotwired/stimulus-loading", to: "stimulus-loading.js"\n)
 
-say "Pin all controllers"
-say %(Appending: pin_all_from "app/javascript/controllers", under: "controllers")
-append_to_file "config/importmap.rb", %(pin_all_from "app/javascript/controllers", under: "controllers"\n)
+  say "Pin all controllers"
+  say %(Appending: pin_all_from "#{javascript_root}/controllers", under: "controllers")
+  append_to_file "config/importmap.rb", %(pin_all_from "#{javascript_root}/controllers", under: "controllers"\n)
+end

lib/install/stimulus_with_node.rb

@@ -1,22 +1,19 @@
-say "Create controllers directory"
-empty_directory "app/javascript/controllers"
-copy_file "#{__dir__}/app/javascript/controllers/index_for_node.js",
-  "app/javascript/controllers/index.js"
-copy_file "#{__dir__}/app/javascript/controllers/application.js",
-  "app/javascript/controllers/application.js"
-copy_file "#{__dir__}/app/javascript/controllers/hello_controller.js",
-  "app/javascript/controllers/hello_controller.js"
+say "Installing Stimulus (for node) into #{destination_root}"
+inside destination_root do
+  say "Create controllers directory"
+  empty_directory "app/javascript/controllers"
+  copy_file "#{__dir__}/app/javascript/controllers/application.js", "app/javascript/controllers/application.js"
+  run "rails generate stimulus hello --without-manifest"
+  run "rails stimulus:manifest:update"
 
-if (Rails.root.join("app/javascript/application.js")).exist?
-  say "Import Stimulus controllers"
-  append_to_file "app/javascript/application.js", %(import "./controllers"\n)
-else
-  say %(Couldn't find "app/javascript/application.js".\nYou must import "./controllers" in your JavaScript entrypoint file), :red
-end
+  if File.exist?("app/javascript/application.js")
+    say "Import Stimulus controllers"
+    append_to_file "app/javascript/application.js", %(import "./controllers"\n)
+  else
+    say %(Couldn't find "app/javascript/application.js".), :red
+    say %(You must import "./controllers" in your JavaScript entrypoint file), :red
+  end
 
-say "Install Stimulus"
-if (Rails.root.join("bun.config.js")).exist?
-  run "bun add @hotwired/stimulus"
-else
+  say "Install Stimulus"
   run "yarn add @hotwired/stimulus"
 end

lib/rake/extensions.rb

@@ -0,0 +1,23 @@
+# Extend Rake to allow unscoping from within a scope/namespace.
+# This allows engine tasks to unscope from :app and define top-level tasks.
+module Rake
+
+  module TaskManager
+    def unscoped
+      current_scope = @scope
+      @scope = Scope.make
+      ns = NameSpace.new(self, @scope)
+      yield(ns)
+      ns
+    ensure
+      @scope = current_scope
+    end
+  end
+
+  module DSL
+    def unscoped(&block)
+      Rake.application.unscoped(&block)
+    end
+  end
+
+end

lib/tasks/stimulus_tasks.rake

@@ -1,46 +1,55 @@
 require "stimulus/manifest"
+require "rake/extensions"
+require "rails/generators"
+require "rails/generators/rails/app/app_generator"
 
 module Stimulus
   module Tasks
     extend self
-    def run_stimulus_install_template(path)
-      system RbConfig.ruby, "./bin/rails", "app:template", "LOCATION=#{File.expand_path("../install/#{path}.rb",  __dir__)}"
+
+    def detect_install_template(root)
+      if root.join("config/importmap.rb").exist?
+        "importmap"
+      elsif root.join("package.json").exist?
+        if root.join("bun.config.js").exist?
+          "bun"
+        else
+          "node"
+        end
+      end
     end
 
-    def using_bun?
-      Rails.root.join("bun.config.js").exist?
+    def self.run_stimulus_install_template(path, root)
+      Rails::Generators::AppGenerator.apply_rails_template(File.expand_path("../install/#{path}.rb", __dir__), root)
     end
+
   end
 end
 
 namespace :stimulus do
   desc "Install Stimulus into the app"
   task :install do
-    if Rails.root.join("config/importmap.rb").exist?
-      Rake::Task["stimulus:install:importmap"].invoke
-    elsif Rails.root.join("package.json").exist? && Stimulus::Tasks.using_bun?
-      Rake::Task["stimulus:install:bun"].invoke
-    elsif Rails.root.join("package.json").exist?
-      Rake::Task["stimulus:install:node"].invoke
+    if (install_template = Stimulus::Tasks.detect_install_template(Rails.root))
+      Stimulus::Tasks.run_stimulus_install_template("stimulus_with_#{install_template}", Rails.root)
     else
       puts "You must either be running with node (package.json) or importmap-rails (config/importmap.rb) to use this gem."
     end
   end
 
   namespace :install do
-    desc "Install Stimulus on an app running importmap-rails"
+    desc "Install Stimulus in an app running importmap-rails"
     task :importmap do
-      Stimulus::Tasks.run_stimulus_install_template "stimulus_with_importmap"
+      Stimulus::Tasks.run_stimulus_install_template("stimulus_with_importmap", Rails.root)
     end
 
-    desc "Install Stimulus on an app running node"
+    desc "Install Stimulus in an app running node"
     task :node do
-      Stimulus::Tasks.run_stimulus_install_template "stimulus_with_node"
+      Stimulus::Tasks.run_stimulus_install_template("stimulus_with_node", Rails.root)
     end
 
-    desc "Install Stimulus on an app running bun"
+    desc "Install Stimulus in an app running bun"
     task :bun do
-      Stimulus::Tasks.run_stimulus_install_template "stimulus_with_bun"
+      Stimulus::Tasks.run_stimulus_install_template("stimulus_with_bun", Rails.root)
     end
   end
 
@@ -52,8 +61,7 @@ namespace :stimulus do
 
     desc "Update the Stimulus manifest (will overwrite controllers/index.js)"
     task :update do
-      manifest =
-        Stimulus::Manifest.generate_from(Rails.root.join("app/javascript/controllers"))
+      manifest = Stimulus::Manifest.generate_from(Rails.root.join("app/javascript/controllers"))
 
       File.open(Rails.root.join("app/javascript/controllers/index.js"), "w+") do |index|
         index.puts "// This file is auto-generated by ./bin/rails stimulus:manifest:update"
@@ -66,3 +74,58 @@ namespace :stimulus do
     end
   end
 end
+
+if defined?(ENGINE_ROOT) && (engine = Rails::Engine.find(ENGINE_ROOT))
+  unscoped do
+    namespace :stimulus do
+
+      desc "Install Stimulus into the engine"
+      task :install do
+        if (install_template = Stimulus::Tasks.detect_install_template(engine.root))
+          Stimulus::Tasks.run_stimulus_install_template("stimulus_with_#{install_template}", engine.root)
+        else
+          puts "You must either be running with node/bun (package.json) or importmap-rails (config/importmap.rb) to use this gem."
+        end
+      end
+
+      namespace :install do
+        desc "Install Stimulus in an engine running importmap-rails"
+        task :importmap do
+          Stimulus::Tasks.run_stimulus_install_template("stimulus_with_importmap", Rails.root)
+        end
+
+        desc "Install Stimulus in an engine running node"
+        task :node do
+          Stimulus::Tasks.run_stimulus_install_template("stimulus_with_node", Rails.root)
+        end
+
+        desc "Install Stimulus in an engine running bun"
+        task :bun do
+          Stimulus::Tasks.run_stimulus_install_template("stimulus_with_bun", Rails.root)
+        end
+      end
+
+      namespace :manifest do
+
+        desc "Show the current engine Stimulus manifest (all installed controllers)"
+        task :display do
+          puts Stimulus::Manifest.generate_from(engine.root.join("app/javascript/controllers"))
+        end
+
+        desc "Update the engine Stimulus manifest (will overwrite controllers/index.js)"
+        task :update do
+          manifest = Stimulus::Manifest.generate_from(engine.root.join("app/javascript/controllers"))
+          File.open(engine.root.join("app/javascript/controllers/index.js"), "w+") do |index|
+            index.puts "// This file is auto-generated by ./bin/rails stimulus:manifest:update"
+            index.puts "// Run that command whenever you add a new controller or create them with"
+            index.puts "// ./bin/rails generate stimulus controllerName"
+            index.puts
+            index.puts %(import { application } from "./application")
+            index.puts manifest
+          end
+        end
+
+      end
+    end
+  end
+end

test/generator_test.rb

@@ -26,7 +26,6 @@ class StimulusGeneratorTest < Rails::Generators::TestCase
     assert_file "app/javascript/controllers/hello_world_controller.js", /data-controller="hello-world"/
   end
 
-
   test "generating with camelized name and lower case first letter" do
     run_generator ["helloWorld"]
 
@@ -46,9 +45,9 @@ class StimulusGeneratorTest < Rails::Generators::TestCase
   end
 
   test "generating with namespaced name" do
-    run_generator ["hello/world"]
+    run_generator ["hello/happy/world"]
 
-    assert_file "app/javascript/controllers/hello/world_controller.js", /data-controller="hello--world"/
+    assert_file "app/javascript/controllers/hello/happy/world_controller.js", /data-controller="hello--happy--world"/
   end
 
   test "generating with namespaced and camelized name" do