Use bun for installation if applicable (#125)

* Add Bun support

* Namespace tasks so they don't conflict

* detect bun usage via presence of bun.config.js

lib/install/stimulus_with_bun.rb

@@ -0,0 +1,18 @@
+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"
+
+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
+
+say "Install Stimulus"
+run "bun add @hotwired/stimulus"

lib/tasks/stimulus_tasks.rake

@@ -1,12 +1,25 @@
 require "stimulus/manifest"
 
-def run_stimulus_install_template(path) system "#{RbConfig.ruby} ./bin/rails app:template LOCATION=#{File.expand_path("../install/#{path}.rb",  __dir__)}" end
+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__)}"
+    end
+
+    def using_bun?
+      Rails.root.join("bun.config.js").exist?
+    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
     else
@@ -17,12 +30,17 @@ namespace :stimulus do
   namespace :install do
     desc "Install Stimulus on an app running importmap-rails"
     task :importmap do
-      run_stimulus_install_template "stimulus_with_importmap"
+      Stimulus::Tasks.run_stimulus_install_template "stimulus_with_importmap"
     end
 
     desc "Install Stimulus on an app running node"
     task :node do
-      run_stimulus_install_template "stimulus_with_node"
+      Stimulus::Tasks.run_stimulus_install_template "stimulus_with_node"
+    end
+
+    desc "Install Stimulus on an app running bun"
+    task :bun do
+      Stimulus::Tasks.run_stimulus_install_template "stimulus_with_bun"
     end
   end