Add yarn_command to GeneratorBase

lib/generators/rolemodel/linters/eslint/eslint_generator.rb

@@ -18,8 +18,7 @@ class EslintGenerator < GeneratorBase
       ].freeze
 
       def install_eslint
-        ensure_yarn
-        run "yarn add --dev #{DEV_DEPENDENCIES.join(' ')}"
+        yarn_command "add --dev #{DEV_DEPENDENCIES.join(' ')}"
       end
 
       def add_config

lib/generators/rolemodel/optics/base/base_generator.rb

@@ -6,8 +6,7 @@ class BaseGenerator < Rolemodel::GeneratorBase
       def add_optics_package
         say 'installing Optics package', :green
 
-        ensure_yarn
-        run 'yarn add @rolemodel/optics'
+        yarn_command 'add @rolemodel/optics'
       end
 
       def copy_templates

lib/generators/rolemodel/react/react_generator.rb

@@ -6,8 +6,7 @@ def add_npm_packages
       @add_react = yes?('Would you like to add react?')
 
       if @add_react
-        ensure_yarn
-        run 'yarn add react react-dom'
+        yarn_command 'add react react-dom'
       end
     end
 

lib/generators/rolemodel/sentry/sentry_generator.rb

@@ -43,8 +43,7 @@ def add_user_context
     def add_js_dependencies
       say 'Adding Sentry JS dependencies to package.json', :green
 
-      ensure_yarn
-      run "yarn add --dev #{JS_DEPS.join(' ')}"
+      yarn_command "add --dev #{JS_DEPS.join(' ')}"
     end
 
     def add_js_initializer

lib/generators/rolemodel/tailored_select/tailored_select_generator.rb

@@ -7,8 +7,7 @@ class TailoredSelectGenerator < GeneratorBase
     def add_tailored_select_package
       say 'Installing Tailored Select package', :green
 
-      ensure_yarn
-      run 'yarn add @rolemodel/tailored-select'
+      yarn_command 'add @rolemodel/tailored-select'
     end
 
     def add_simple_form_input

lib/generators/rolemodel/testing/jasmine_playwright/jasmine_playwright_generator.rb

@@ -18,8 +18,10 @@ def fail_without_github_token
         raise Thor::InvocationError, 'a --github_package_token option or GITHUB_PACKAGES_TOKEN environment variable is required' if options[:github_package_token].blank?
       end
 
-      def enable_corepack_and_yarn
-        ensure_yarn
+      def add_dev_dependencies
+        say 'Adding new dev dependency to package.json', :green
+
+        yarn_command "add --dev #{DEV_DEPENDENCIES.join(' ')}"
       end
 
       def add_browser_test_script
@@ -34,12 +36,6 @@ def set_node_version
         create_file '.node-version', NODE_VERSION, force: true
       end
 
-      def add_dev_dependencies
-        say 'Adding new dev dependency to package.json', :green
-
-        run "yarn add --dev #{DEV_DEPENDENCIES.join(' ')}"
-      end
-
       def add_spec_config_files
         say 'Adding Jasmine Playwright configuration files', :green
 

lib/generators/rolemodel/testing/rspec/rspec_generator.rb

@@ -27,9 +27,8 @@ def bundle_install
       def install_playwright
         say 'Installing Playwright for system tests', :green
 
-        ensure_yarn
-        run 'yarn add --dev playwright'
-        run 'yarn run playwright install'
+        yarn_command 'add --dev playwright'
+        yarn_command 'run playwright install'
       end
 
       def add_spec_files

lib/generators/rolemodel/testing/vitest/vitest_generator.rb

@@ -14,17 +14,16 @@ class VitestGenerator < GeneratorBase
         @vitest/ui
       ].freeze
 
-      def update_test_script
-        say 'Update yarn test command', :green
-        ensure_yarn
+      def add_dev_dependencies
+        say 'Adding new dev dependency to package.json', :green
 
-        add_package_json_script 'test', TEST_COMMAND
+        yarn_command "add --dev #{DEV_DEPENDENCIES.join(' ')}"
       end
 
-      def add_dev_dependencies
-        say 'Adding new dev dependency to package.json', :green
+      def update_test_script
+        say 'Update yarn test command', :green
 
-        run "yarn add --dev #{DEV_DEPENDENCIES.join(' ')}"
+        add_package_json_script 'test', TEST_COMMAND
       end
 
       def add_spec_config_files

lib/generators/rolemodel/turbo/confirm/confirm_generator.rb

@@ -6,8 +6,7 @@ class ConfirmGenerator < ::Rolemodel::GeneratorBase
       def add_turbo_confirm_package
         say 'Installing Turbo Confirm package', :green
 
-        ensure_yarn
-        run 'yarn add @rolemodel/turbo-confirm'
+        yarn_command 'add @rolemodel/turbo-confirm'
       end
 
       def add_initializer

lib/generators/rolemodel/turbo/form/form_generator.rb

@@ -6,8 +6,7 @@ class FormGenerator < GeneratorBase
       def add_rails_request_package
         say 'Installing @rails/request.js package', :green
 
-        ensure_yarn
-        run 'yarn add @rails/request.js'
+        yarn_command 'add @rails/request.js'
       end
 
       def add_stimulus_controller

lib/generators/rolemodel/ui_components/navbar/navbar_generator.rb

@@ -25,8 +25,7 @@ def insert_navbar_before_content
       def install_shoelace
         say 'Installing Shoelace package', :green
 
-        ensure_yarn
-        run 'yarn add @shoelace-style/shoelace'
+        yarn_command 'add @shoelace-style/shoelace'
       end
 
       def add_shoelace_javascript_imports

lib/generators/rolemodel/webpack/webpack_generator.rb

@@ -41,12 +41,6 @@ def ensure_node_version
       create_file '.node-version', NODE_VERSION, force: true
     end
 
-    def enable_corepack_and_yarn
-      say 'Enabling Corepack and pinning the project to Yarn 4+', :green
-
-      ensure_yarn
-    end
-
     def force_node_to_use_es_modules
       say 'Configuring project to use ES Modules instead of CommonJS', :green
 
@@ -56,14 +50,14 @@ def force_node_to_use_es_modules
     def remove_obsolete_javascript_dependencies
       say 'Removing webpack & webpack-cli from package.json dependencies', :green
 
-      run 'yarn remove webpack webpack-cli'
+      yarn_command 'remove webpack webpack-cli'
     end
 
     def add_npm_packages
       say 'Adding new dev dependencies to package.json', :green
 
       dependencies = DEV_DEPS + POSTCSS_PKGS + WEBPACK_CSS_PKGS
-      run "yarn add --dev #{dependencies.join(' ')}"
+      yarn_command "add --dev #{dependencies.join(' ')}"
     end
 
     def add_webpack_config

lib/rolemodel/generator_base.rb

@@ -9,19 +9,25 @@ module Rolemodel
   class GeneratorBase < ::Rails::Generators::Base
     include ::Rails::Generators::BundleHelper, ReplaceContentHelper
 
-
     private
     # based on https://github.com/rails/rails/blob/main/railties/lib/rails/generators/app_base.rb#L713
     def run_bundle
       bundle_command("install --quiet", "BUNDLE_IGNORE_MESSAGES" => "1")
     end
 
+    def yarn_command(command)
+      ensure_yarn
+
+      run "yarn #{command}"
+    end
+
     # Enable Corepack and pin the project to Yarn 4+ before running any `yarn`
     # command. Empty args/opts are required: without them, Thor forwards this
     # generator's own CLI args (e.g. the test harness's --skip-bundle
     # --skip-bootsnap) into Rolemodel::Yarn#setup, which takes none and raises
     # Thor::InvocationError.
     def ensure_yarn
+      return if Rails.root.join(destination_root, '.yarnrc.yml').exist?
       invoke 'rolemodel:yarn:setup', [], {}
     end
 

lib/rolemodel/yarn.rb

@@ -5,11 +5,10 @@ module Rolemodel
   class Yarn < ::Thor
     include ::Thor::Actions
 
-    # Enable Corepack and pin the project to Yarn 4+ (instead of the classic
-    # Yarn 1.22). Idempotent, so any generator can call it before running a
-    # `yarn` command to guarantee the modern toolchain is in place.
+    # Enable Corepack and pin the project to Yarn 4+ (instead of the classic Yarn 1.22).
     desc 'setup', 'Set the current stable version of Yarn, enable corepack, and initialize a package.json file'
     def setup
+      say 'Setting up Yarn 4+ and Corepack', :green
       # Configure the node-modules linker so webpack, Playwright, and the Rails
       # asset pipeline keep working (Yarn 4 defaults to Plug'n'Play otherwise).
       # skip if exists? to avoid overwriting any other existing config