Add support for installing via rails mounted engines

.gitignore

@@ -1,2 +1,6 @@
 *.gem
 /node_modules
+
+test/rake_tasks/mounted_apps/webpacker/node_modules
+test/rake_tasks/mounted_apps/webpacker/log
+test/rake_tasks/mounted_apps/asset_pipeline/log

Gemfile

@@ -12,4 +12,5 @@ group :test do
   gem 'selenium-webdriver'
   gem 'webdrivers'
   gem 'sqlite3'
+  gem 'webpacker'
 end

Gemfile.lock

@@ -105,6 +105,8 @@ GEM
       nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)
+    rack-proxy (0.6.5)
+      rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
     rails (6.1.3.2)
@@ -140,6 +142,7 @@ GEM
     selenium-webdriver (3.142.7)
       childprocess (>= 0.5, < 4.0)
       rubyzip (>= 1.2.2)
+    semantic_range (3.0.0)
     sprockets (4.0.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -155,6 +158,11 @@ GEM
       nokogiri (~> 1.6)
       rubyzip (>= 1.3.0)
       selenium-webdriver (>= 3.0, < 4.0)
+    webpacker (5.2.1)
+      activesupport (>= 5.2)
+      rack-proxy (>= 0.6.1)
+      railties (>= 5.2)
+      semantic_range (>= 2.3.0)
     websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
     websocket-extensions (0.1.5)
@@ -175,6 +183,7 @@ DEPENDENCIES
   sqlite3
   turbo-rails!
   webdrivers
+  webpacker
 
 BUNDLED WITH
    2.2.16

README.md

@@ -47,6 +47,19 @@ The `Turbo` instance is automatically assigned to `window.Turbo` upon import:
 ```js
 import "@hotwired/turbo-rails"
 ```
+### Installing on Mounted Engines
+The setup for use in a mounted engine will involve the following steps:
+
+1. Add the `turbo-rails` gem to your gemspec file: `spec.add_dependency "turbo-rails"`
+2. Run `./bin/bundle install`
+3. Run `./bin/rails app:turbo:install`
+4. Add `require "turbo-rails"` to your Rails::Engine subclass file (e.g. `lib/blorgh/engine.rb`)
+5. Add a similar initializer for your assets to that same Rails::Engine file:
+```ruby
+initializer "blorgh.assets.precompile" do |app|
+  app.config.assets.precompile += %w( blorgh/application.css )
+end
+```
 
 ## Usage
 

lib/install/turbo_with_asset_pipeline.rb

@@ -1,36 +1,67 @@
-APPLICATION_LAYOUT_PATH = Rails.root.join("app/views/layouts/application.html.erb")
-IMPORTMAP_PATH = Rails.root.join("app/assets/javascripts/importmap.json.erb")
-CABLE_CONFIG_PATH = Rails.root.join("config/cable.yml")
+app_layout_path = Rails.root.join("app/views/layouts/application.html.erb")
+importmap_path = Rails.root.join("app/assets/javascripts/importmap.json.erb")
+cable_config_path = Rails.root.join("config/cable.yml")
 
-if APPLICATION_LAYOUT_PATH.exist?
+def engine_root
+  defined?(ENGINE_ROOT) && Pathname.new(ENGINE_ROOT)
+end
+
+if engine_root
+  engine_name = File.basename(ENGINE_ROOT)
+  app_layout_path = engine_root.join("app/views/layouts/#{engine_name}/application.html.erb")
+  importmap_path = engine_root.join("app/assets/javascripts/#{engine_name}/importmap.json.erb")
+end
+
+if app_layout_path.exist?
   say "Yield head in application layout for cache helper"
-  insert_into_file APPLICATION_LAYOUT_PATH.to_s, "\n    <%= yield :head %>", before: /\s*<\/head>/
+  insert_into_file app_layout_path.to_s, "\n    <%= yield :head %>", before: /\s*<\/head>/
 
-  if APPLICATION_LAYOUT_PATH.read =~ /stimulus/
+  if app_layout_path.read =~ /stimulus/
     say "Add Turbo include tags in application layout"
-    insert_into_file APPLICATION_LAYOUT_PATH.to_s, %(\n    <%= javascript_include_tag "turbo", type: "module-shim" %>), after: /<%= stimulus_include_tags %>/
+    insert_into_file app_layout_path.to_s, %(\n    <%= javascript_include_tag "turbo", type: "module-shim" %>), after: /<%= stimulus_include_tags %>/
 
-    if IMPORTMAP_PATH.exist?
+    if importmap_path.exist?
       say "Add Turbo to importmap"
-      insert_into_file IMPORTMAP_PATH, %(    "turbo": "<%= asset_path "turbo" %>",\n), after: /  "imports": {\s*\n/
+      insert_into_file importmap_path, %(    "turbo": "<%= asset_path "turbo" %>",\n), after: /  "imports": {\s*\n/
     end
   else
     say "Add Turbo include tags in application layout"
-    insert_into_file APPLICATION_LAYOUT_PATH.to_s, %(\n    <%= javascript_include_tag "turbo", type: "module" %>), before: /\s*<\/head>/
+    insert_into_file app_layout_path.to_s, %(\n    <%= javascript_include_tag "turbo", type: "module" %>), before: /\s*<\/head>/
   end
 else
   say "Default application.html.erb is missing!", :red
   say %(        Add <%= javascript_include_tag("turbo", type: "module-shim") %> and <%= yield :head %> within the <head> tag after Stimulus includes in your custom layout.)
 end
 
-if CABLE_CONFIG_PATH.exist?
-  say "Enable redis in bundle"
-  uncomment_lines "Gemfile", %(gem 'redis')
+if engine_root
+  say "Appending redis to Gemfile"
+  append_to_file engine_root.join("Gemfile"), %(gem 'redis')
 
-  say "Switch development cable to use redis"
-  gsub_file CABLE_CONFIG_PATH.to_s, /development:\n\s+adapter: async/, "development:\n  adapter: redis\n  url: redis://localhost:6379/1"
+  say "Create config/cable.yml to use redis"
+  create_file engine_root.join("config/cable.yml") do
+    <<~FILE
+      development:
+        adapter: redis
+        url: redis://localhost:6379/1
+      test:
+        adapter: test
+
+      production:
+        adapter: redis
+        url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
+        channel_prefix: dummy_production
+    FILE
+  end
 else
-  say 'ActionCable config file (config/cable.yml) is missing. Uncomment "gem \'redis\'" in your Gemfile and create config/cable.yml to use the Turbo Streams broadcast feature.'
+	if cable_config_path.exist?
+		say "Enable redis in bundle"
+		uncomment_lines "Gemfile", %(gem 'redis')
+
+		say "Switch development cable to use redis"
+		gsub_file cable_config_path, /development:\n\s+adapter: async/, "development:\n  adapter: redis\n  url: redis://localhost:6379/1"
+	else
+		say 'ActionCable config file (config/cable.yml) is missing. Uncomment "gem \'redis\'" in your Gemfile and create config/cable.yml to use the Turbo Streams broadcast feature.'
+	end
 end
 
 say "Turbo successfully installed ⚡️", :green

lib/install/turbo_with_webpacker.rb

@@ -1,7 +1,7 @@
 # Some Rails versions use commonJS(require) others use ESM(import).
 TURBOLINKS_REGEX = /(import .* from "turbolinks".*\n|require\("turbolinks"\).*\n)/.freeze
 ACTIVE_STORAGE_REGEX = /(import.*ActiveStorage|require.*@rails\/activestorage.*)/.freeze
-CABLE_CONFIG_PATH = Rails.root.join("config/cable.yml")
+cable_config_path = Rails.root.join("config/cable.yml")
 
 abort "❌ Webpacker not found. Exiting." unless defined?(Webpacker::Engine)
 
@@ -16,14 +16,37 @@
 gsub_file "#{Webpacker.config.source_entry_path}/application.js", TURBOLINKS_REGEX, ''
 gsub_file "#{Webpacker.config.source_entry_path}/application.js", /Turbolinks.start.*\n/, ''
 
-if CABLE_CONFIG_PATH.exist?
-  say "Enable redis in bundle"
-  uncomment_lines "Gemfile", %(gem 'redis')
+engine_root = defined?(ENGINE_ROOT) && Pathname.new(ENGINE_ROOT)
+if engine_root
+  say "Appending redis to Gemfile"
+  append_to_file engine_root.join("Gemfile"), %(gem 'redis')
 
-  say "Switch development cable to use redis"
-  gsub_file CABLE_CONFIG_PATH.to_s, /development:\n\s+adapter: async/, "development:\n  adapter: redis\n  url: redis://localhost:6379/1"
+  say "Create config/cable.yml to use redis"
+  create_file engine_root.join("config/cable.yml") do
+    <<~FILE
+      development:
+        adapter: redis
+        url: redis://localhost:6379/1
+
+      test:
+        adapter: test
+
+      production:
+        adapter: redis
+        url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
+        channel_prefix: dummy_production
+    FILE
+  end
 else
-  say 'ActionCable config file (config/cable.yml) is missing. Uncomment "gem \'redis\'" in your Gemfile and create config/cable.yml to use the Turbo Streams broadcast feature.'
+  if cable_config_path.exist?
+    say "Enable redis in bundle"
+    uncomment_lines "Gemfile", %(gem 'redis')
+
+    say "Switch development cable to use redis"
+    gsub_file cable_config_path, /development:\n\s+adapter: async/, "development:\n  adapter: redis\n  url: redis://localhost:6379/1"
+  else
+    say 'ActionCable config file (config/cable.yml) is missing. Uncomment "gem \'redis\'" in your Gemfile and create config/cable.yml to use the Turbo Streams broadcast feature.'
+  end
 end
 
 say "Turbo successfully installed ⚡️", :green

lib/tasks/turbo_tasks.rake

@@ -1,24 +1,29 @@
-def run_turbo_install_template(path) system "#{RbConfig.ruby} ./bin/rails app:template LOCATION=#{File.expand_path("../install/#{path}.rb",  __dir__)}" end
+def run_turbo_install_template(path, nspace = nil)
+  system "#{RbConfig.ruby} #{Rails.root}/bin/rails #{nspace}app:template LOCATION=#{File.expand_path("../install/#{path}.rb",  __dir__)}"
+end
 
 namespace :turbo do
   desc "Install Turbo into the app"
-  task :install do
+  task :install do |task|
+    nspace = task.name.split(/turbo:install/).first
     if defined?(Webpacker::Engine)
-      Rake::Task["turbo:install:webpacker"].invoke
+      Rake::Task["#{nspace}turbo:install:webpacker"].invoke
     else
-      Rake::Task["turbo:install:asset_pipeline"].invoke
+      Rake::Task["#{nspace}turbo:install:asset_pipeline"].invoke
     end
   end
 
   namespace :install do
     desc "Install Turbo into the app with asset pipeline"
-    task :asset_pipeline do
-      run_turbo_install_template "turbo_with_asset_pipeline"
+    task :asset_pipeline do |task|
+      nspace = task.name.split(/turbo:install/).first
+      run_turbo_install_template "turbo_with_asset_pipeline", nspace
     end
 
     desc "Install Turbo into the app with webpacker"
-    task :webpacker do
-      run_turbo_install_template "turbo_with_webpacker"
+    task :webpacker do |task|
+      nspace = task.name.split(/turbo:install/).first
+      run_turbo_install_template "turbo_with_webpacker", nspace
     end
   end
 end

test/fixtures/files/Gemfile

@@ -0,0 +1,4 @@
+source 'https://rubygems.org'
+
+# Use Redis adapter to run Action Cable in production
+# gem 'redis', '~> 4.0'

test/fixtures/files/application.html.erb

@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title><%= camelized %></title>
+    <%= csrf_meta_tags %>
+    <%= csp_meta_tag %>
+
+    <%- if options[:skip_javascript] -%>
+    <%= stylesheet_link_tag "application" %>
+    <%- else -%>
+      <%- unless options[:skip_turbolinks] -%>
+    <%= stylesheet_link_tag "application", "data-turbolinks-track": "reload" %>
+    <%= javascript_pack_tag "application", "data-turbolinks-track": "reload" %>
+      <%- else -%>
+    <%= stylesheet_link_tag "application" %>
+    <%= javascript_pack_tag "application" %>
+      <%- end -%>
+    <%- end -%>
+  </head>
+
+  <body>
+    <%= yield %>
+  </body>
+</html>

test/fixtures/files/cable.yml

@@ -0,0 +1,10 @@
+development:
+  adapter: async
+
+test:
+  adapter: test
+
+production:
+  adapter: redis
+  url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
+  channel_prefix: blah_production

test/rake_task_test_helper.rb

@@ -0,0 +1,22 @@
+module RakeTaskTestHelper
+  def setup
+    app_layout = File.join(fixtures_path, "application.html.erb")
+    gemfile = File.join(fixtures_path, "Gemfile")
+    cablefile = File.join(fixtures_path, "cable.yml")
+
+    FileUtils.mkpath File.join(app_path, "app", "views", "layouts")
+    FileUtils.cp app_layout, File.join(app_path, "app", "views", "layouts", "application.html.erb")
+    FileUtils.cp gemfile, File.join(app_path, "Gemfile")
+    FileUtils.cp cablefile, File.join(app_path, "config", "cable.yml")
+  end
+
+  def teardown
+    FileUtils.rm File.join(app_path, "app", "views", "layouts", "application.html.erb")
+    FileUtils.rm File.join(app_path, "Gemfile")
+    FileUtils.rm File.join(app_path, "config", "cable.yml")
+  end
+
+  def fixtures_path
+    File.expand_path("fixtures/files", __dir__)
+  end
+end

test/rake_tasks/engine_asset_pipeline_rake_tasks_test.rb

@@ -0,0 +1,25 @@
+require 'rake_task_test_helper'
+
+class EngineAssetPipelineRakeTasksTest < Minitest::Test
+  include RakeTaskTestHelper
+
+  def test_tasks_are_listed_on_asset_pipeline_app
+    output = Dir.chdir(app_path) { `rake -T` }
+
+    assert_includes output, "app:turbo"
+    assert_includes output, "app:turbo:install"
+    assert_includes output, "app:turbo:install:asset_pipeline"
+  end
+
+  def test_asset_pipeline_based_install
+    output = Dir.chdir(app_path) { `bundle exec rake app:turbo:install` }
+
+    assert_includes output, "Turbo successfully installed ⚡"
+  end
+
+  private
+
+  def app_path
+    File.expand_path("mounted_apps/asset_pipeline", __dir__)
+  end
+end

test/rake_tasks/engine_webpacker_rake_tasks_test.rb

@@ -0,0 +1,31 @@
+require 'rake_task_test_helper'
+
+class EngineWebpackerRakeTasksTest < Minitest::Test
+  include RakeTaskTestHelper
+
+  def teardown
+    nmodules_path = File.join(app_path, "node_modules")
+    FileUtils.rm_rf nmodules_path if File.directory?(nmodules_path)
+    super
+  end
+
+  def test_tasks_are_listed_on_webpacker_app
+    output = Dir.chdir(app_path) { `rake -T` }
+
+    assert_includes output, "app:turbo"
+    assert_includes output, "app:turbo:install"
+    assert_includes output, "app:turbo:install:webpacker"
+  end
+
+  def test_webpacker_based_install
+    output = Dir.chdir(app_path) { `bundle exec rake app:turbo:install` }
+
+    assert_includes output, "Turbo successfully installed ⚡"
+  end
+
+  private
+
+  def app_path
+    File.expand_path("mounted_apps/webpacker", __dir__)
+  end
+end

test/rake_tasks/mounted_apps/asset_pipeline/Rakefile

@@ -0,0 +1,4 @@
+require "bundler/setup"
+
+APP_RAKEFILE = File.expand_path("app_rakefile", __dir__)
+load "rails/tasks/engine.rake"

test/rake_tasks/mounted_apps/asset_pipeline/app_rakefile

@@ -0,0 +1,3 @@
+require_relative "config/application"
+
+Rails.application.load_tasks

test/rake_tasks/mounted_apps/asset_pipeline/bin/rails

@@ -0,0 +1,3 @@
+#!/usr/bin/env ruby
+APP_PATH = File.expand_path("../config/application", __dir__)
+require "rails/commands"

test/rake_tasks/mounted_apps/asset_pipeline/bin/rake

@@ -0,0 +1,3 @@
+#!/usr/bin/env ruby
+require "rake"
+Rake.application.run

test/rake_tasks/mounted_apps/asset_pipeline/config.ru

@@ -0,0 +1,5 @@
+# This file allows the `Rails.root` to be correctly determined.
+
+require_relative "config/environment"
+
+run Rails.application