Run webpacker:install to update executables on bin/

spec/dummy/.gitignore

@@ -21,3 +21,8 @@
 /public/webpack/*
 
 /spec/examples.txt
+
+# Webpack v6 installer additions
+/yarn-error.log
+yarn-debug.log*
+.yarn-integrity

spec/dummy/bin/webpack

@@ -1,19 +1,15 @@
 #!/usr/bin/env ruby
 
-ENV["RAILS_ENV"] ||= ENV["RACK_ENV"] || "development"
-ENV["NODE_ENV"]  ||= "development"
-
 require "pathname"
-ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../Gemfile",
-  Pathname.new(__FILE__).realpath)
-
 require "bundler/setup"
-
 require "webpacker"
 require "webpacker/webpack_runner"
 
-APP_ROOT = File.expand_path("..", __dir__)
+ENV["RAILS_ENV"] ||= ENV["RACK_ENV"] || "development"
+ENV["NODE_ENV"]  ||= "development"
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../Gemfile", Pathname.new(__FILE__).realpath)
 
+APP_ROOT = File.expand_path("..", __dir__)
 Dir.chdir(APP_ROOT) do
   Webpacker::WebpackRunner.run(ARGV)
 end

spec/dummy/bin/webpack-dev-server

@@ -2,6 +2,7 @@
 
 ENV["RAILS_ENV"] ||= ENV["RACK_ENV"] || "development"
 ENV["NODE_ENV"]  ||= "development"
+
 require "pathname"
 ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../Gemfile",
   Pathname.new(__FILE__).realpath)

spec/dummy/bin/yarn

@@ -0,0 +1,18 @@
+#!/usr/bin/env ruby
+
+APP_ROOT = File.expand_path("..", __dir__)
+Dir.chdir(APP_ROOT) do
+  yarn = ENV["PATH"].split(File::PATH_SEPARATOR).
+    select { |dir| File.expand_path(dir) != __dir__ }.
+    product(["yarn", "yarnpkg", "yarn.cmd", "yarn.ps1"]).
+    map { |dir, file| File.expand_path(file, dir) }.
+    find { |file| File.executable?(file) }
+
+  if yarn
+    exec yarn, *ARGV
+  else
+    $stderr.puts "Yarn executable was not detected in the system."
+    $stderr.puts "Download Yarn at https://yarnpkg.com/en/docs/install"
+    exit 1
+  end
+end

spec/dummy/config/initializers/assets.rb

@@ -11,3 +11,6 @@
 # Precompile additional assets.
 # application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
 # Rails.application.config.assets.precompile += %w( search.js )
+
+# Add node_modules folder to the asset load path.
+Rails.application.config.assets.paths << Rails.root.join("node_modules")

spec/dummy/package.json

@@ -8,7 +8,7 @@
   "private": true,
   "dependencies": {
     "@babel/preset-react": "^7.10.4",
-    "@rails/webpacker": "6.0.0-rc.6",
+    "@rails/webpacker": "^6.0.0-rc.6",
     "babel-plugin-macros": "^3.1.0",
     "babel-plugin-module-resolver": "^4.0.0",
     "core-js": "3",
@@ -44,11 +44,14 @@
     "sass-resources-loader": "^2.1.0",
     "style-loader": "^3.3.1",
     "url-loader": "^4.0.0",
+    "webpack": "^5.53.0",
+    "webpack-cli": "^4.8.0",
     "webpack-dev-server": "^4.5.0",
     "webpack-merge": "^5.1.4"
   },
   "devDependencies": {
     "@pmmmwh/react-refresh-webpack-plugin": "0.4.2",
+    "@webpack-cli/serve": "^1.6.0",
     "react-refresh": "^0.8.1"
   },
   "browser": {