Enhance bin/dev error messages with verbose flag suggestion

When bin/dev fails with non-zero exit code, users now see a helpful
suggestion to run with --verbose flag for detailed output. This improves
the debugging experience by making it clear how to get more information.

Additionally, the --verbose flag now properly propagates to child processes
like pack generation through the REACT_ON_RAILS_VERBOSE environment variable.

Changes:
- PackGenerator suggests --verbose flag on failure (unless already verbose)
- Verbose mode propagates via REACT_ON_RAILS_VERBOSE env var to child processes
- PacksGenerator respects verbose flag to control output verbosity
- Rake task generate_packs respects REACT_ON_RAILS_VERBOSE env var
- Added comprehensive tests for verbose flag behavior

This addresses the issue where bin/dev failures showed terse error
messages without guidance on how to get detailed diagnostic output.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

lib/react_on_rails/dev/pack_generator.rb

@@ -38,29 +38,40 @@ def generate(verbose: false)
 
           if verbose
             puts "📦 Generating React on Rails packs..."
-            success = run_pack_generation
+            success = run_pack_generation(verbose: true)
           else
             print "📦 Generating packs... "
-            success = run_pack_generation(silent: true)
+            success = run_pack_generation(silent: true, verbose: false)
             puts success ? "✅" : "❌"
           end
 
           return if success
 
           puts "❌ Pack generation failed"
+          unless verbose
+            puts ""
+            puts "💡 Run with #{Rainbow('--verbose').cyan.bold} flag for detailed output:"
+            puts "   #{Rainbow('bin/dev --verbose').green.bold}"
+          end
           exit 1
         end
 
         private
 
-        def run_pack_generation(silent: false)
+        def run_pack_generation(silent: false, verbose: false)
+          # Set environment variable for child processes to respect verbose mode
+          ENV["REACT_ON_RAILS_VERBOSE"] = verbose ? "true" : "false"
+
           # If we're already inside a Bundler context AND Rails is available (e.g., called from bin/dev),
           # we can directly require and run the task. Otherwise, use bundle exec.
           if should_run_directly?
             run_rake_task_directly(silent: silent)
           else
             run_via_bundle_exec(silent: silent)
           end
+        ensure
+          # Clean up environment variable
+          ENV.delete("REACT_ON_RAILS_VERBOSE")
         end
 
         def should_run_directly?

lib/react_on_rails/packs_generator.rb

@@ -25,40 +25,42 @@ def react_on_rails_npm_package
     def generate_packs_if_stale
       return unless ReactOnRails.configuration.auto_load_bundle
 
+      verbose = ENV["REACT_ON_RAILS_VERBOSE"] == "true"
+
       add_generated_pack_to_server_bundle
 
       # Clean any non-generated files from directories
-      clean_non_generated_files_with_feedback
+      clean_non_generated_files_with_feedback(verbose: verbose)
 
       are_generated_files_present_and_up_to_date = Dir.exist?(generated_packs_directory_path) &&
                                                    File.exist?(generated_server_bundle_file_path) &&
                                                    !stale_or_missing_packs?
 
       if are_generated_files_present_and_up_to_date
-        puts Rainbow("✅ Generated packs are up to date, no regeneration needed").green
+        puts Rainbow("✅ Generated packs are up to date, no regeneration needed").green if verbose
         return
       end
 
-      clean_generated_directories_with_feedback
-      generate_packs
+      clean_generated_directories_with_feedback(verbose: verbose)
+      generate_packs(verbose: verbose)
     end
 
     private
 
-    def generate_packs
-      common_component_to_path.each_value { |component_path| create_pack(component_path) }
-      client_component_to_path.each_value { |component_path| create_pack(component_path) }
+    def generate_packs(verbose: false)
+      common_component_to_path.each_value { |component_path| create_pack(component_path, verbose: verbose) }
+      client_component_to_path.each_value { |component_path| create_pack(component_path, verbose: verbose) }
 
-      create_server_pack if ReactOnRails.configuration.server_bundle_js_file.present?
+      create_server_pack(verbose: verbose) if ReactOnRails.configuration.server_bundle_js_file.present?
     end
 
-    def create_pack(file_path)
+    def create_pack(file_path, verbose: false)
       output_path = generated_pack_path(file_path)
       content = pack_file_contents(file_path)
 
       File.write(output_path, content)
 
-      puts(Rainbow("Generated Packs: #{output_path}").yellow)
+      puts(Rainbow("Generated Packs: #{output_path}").yellow) if verbose
     end
 
     def first_js_statement_in_code(content) # rubocop:disable Metrics/CyclomaticComplexity,Metrics/PerceivedComplexity
@@ -126,11 +128,11 @@ def pack_file_contents(file_path)
       FILE_CONTENT
     end
 
-    def create_server_pack
+    def create_server_pack(verbose: false)
       File.write(generated_server_bundle_file_path, generated_server_pack_file_content)
 
       add_generated_pack_to_server_bundle
-      puts(Rainbow("Generated Server Bundle: #{generated_server_bundle_file_path}").orange)
+      puts(Rainbow("Generated Server Bundle: #{generated_server_bundle_file_path}").orange) if verbose
     end
 
     def build_server_pack_content(component_on_server_imports, server_components, client_components)
@@ -200,17 +202,17 @@ def generated_server_bundle_file_path
       "#{generated_nonentrypoints_path}/#{generated_server_bundle_file_name}.js"
     end
 
-    def clean_non_generated_files_with_feedback
+    def clean_non_generated_files_with_feedback(verbose: false)
       directories_to_clean = [generated_packs_directory_path, generated_server_bundle_directory_path].compact.uniq
       expected_files = build_expected_files_set
 
-      puts Rainbow("🧹 Cleaning non-generated files...").yellow
+      puts Rainbow("🧹 Cleaning non-generated files...").yellow if verbose
 
       total_deleted = directories_to_clean.sum do |dir_path|
-        clean_unexpected_files_from_directory(dir_path, expected_files)
+        clean_unexpected_files_from_directory(dir_path, expected_files, verbose: verbose)
       end
 
-      display_cleanup_summary(total_deleted)
+      display_cleanup_summary(total_deleted, verbose: verbose) if verbose
     end
 
     def build_expected_files_set
@@ -225,17 +227,17 @@ def build_expected_files_set
       { pack_files: expected_pack_files, server_bundle: expected_server_bundle }
     end
 
-    def clean_unexpected_files_from_directory(dir_path, expected_files)
+    def clean_unexpected_files_from_directory(dir_path, expected_files, verbose: false)
       return 0 unless Dir.exist?(dir_path)
 
       existing_files = Dir.glob("#{dir_path}/**/*").select { |f| File.file?(f) }
       unexpected_files = find_unexpected_files(existing_files, dir_path, expected_files)
 
       if unexpected_files.any?
-        delete_unexpected_files(unexpected_files, dir_path)
+        delete_unexpected_files(unexpected_files, dir_path, verbose: verbose)
         unexpected_files.length
       else
-        puts Rainbow("   No unexpected files found in #{dir_path}").cyan
+        puts Rainbow("   No unexpected files found in #{dir_path}").cyan if verbose
         0
       end
     end
@@ -250,31 +252,39 @@ def find_unexpected_files(existing_files, dir_path, expected_files)
       end
     end
 
-    def delete_unexpected_files(unexpected_files, dir_path)
-      puts Rainbow("   Deleting #{unexpected_files.length} unexpected files from #{dir_path}:").cyan
-      unexpected_files.each do |file|
-        puts Rainbow("     - #{File.basename(file)}").blue
-        File.delete(file)
+    def delete_unexpected_files(unexpected_files, dir_path, verbose: false)
+      if verbose
+        puts Rainbow("   Deleting #{unexpected_files.length} unexpected files from #{dir_path}:").cyan
+        unexpected_files.each do |file|
+          puts Rainbow("     - #{File.basename(file)}").blue
+          File.delete(file)
+        end
+      else
+        unexpected_files.each { |file| File.delete(file) }
       end
     end
 
-    def display_cleanup_summary(total_deleted)
+    def display_cleanup_summary(total_deleted, verbose: false)
+      return unless verbose
+
       if total_deleted.positive?
         puts Rainbow("🗑️  Deleted #{total_deleted} unexpected files total").red
       else
         puts Rainbow("✨ No unexpected files to delete").green
       end
     end
 
-    def clean_generated_directories_with_feedback
+    def clean_generated_directories_with_feedback(verbose: false)
       directories_to_clean = [
         generated_packs_directory_path,
         generated_server_bundle_directory_path
       ].compact.uniq
 
-      puts Rainbow("🧹 Cleaning generated directories...").yellow
+      puts Rainbow("🧹 Cleaning generated directories...").yellow if verbose
+
+      total_deleted = directories_to_clean.sum { |dir_path| clean_directory_with_feedback(dir_path, verbose: verbose) }
 
-      total_deleted = directories_to_clean.sum { |dir_path| clean_directory_with_feedback(dir_path) }
+      return unless verbose
 
       if total_deleted.positive?
         puts Rainbow("🗑️  Deleted #{total_deleted} generated files total").red
@@ -283,27 +293,29 @@ def clean_generated_directories_with_feedback
       end
     end
 
-    def clean_directory_with_feedback(dir_path)
-      return create_directory_with_feedback(dir_path) unless Dir.exist?(dir_path)
+    def clean_directory_with_feedback(dir_path, verbose: false)
+      return create_directory_with_feedback(dir_path, verbose: verbose) unless Dir.exist?(dir_path)
 
       files = Dir.glob("#{dir_path}/**/*").select { |f| File.file?(f) }
 
       if files.any?
-        puts Rainbow("   Deleting #{files.length} files from #{dir_path}:").cyan
-        files.each { |file| puts Rainbow("     - #{File.basename(file)}").blue }
+        if verbose
+          puts Rainbow("   Deleting #{files.length} files from #{dir_path}:").cyan
+          files.each { |file| puts Rainbow("     - #{File.basename(file)}").blue }
+        end
         FileUtils.rm_rf(dir_path)
         FileUtils.mkdir_p(dir_path)
         files.length
       else
-        puts Rainbow("   Directory #{dir_path} is already empty").cyan
+        puts Rainbow("   Directory #{dir_path} is already empty").cyan if verbose
         FileUtils.rm_rf(dir_path)
         FileUtils.mkdir_p(dir_path)
         0
       end
     end
 
-    def create_directory_with_feedback(dir_path)
-      puts Rainbow("   Directory #{dir_path} does not exist, creating...").cyan
+    def create_directory_with_feedback(dir_path, verbose: false)
+      puts Rainbow("   Directory #{dir_path} does not exist, creating...").cyan if verbose
       FileUtils.mkdir_p(dir_path)
       0
     end

lib/tasks/generate_packs.rake

@@ -17,18 +17,24 @@ namespace :react_on_rails do
   DESC
 
   task generate_packs: :environment do
-    puts Rainbow("🚀 Starting React on Rails pack generation...").bold
-    puts Rainbow("📁 Auto-load bundle: #{ReactOnRails.configuration.auto_load_bundle}").cyan
-    puts Rainbow("📂 Components subdirectory: #{ReactOnRails.configuration.components_subdirectory}").cyan
-    puts ""
+    verbose = ENV["REACT_ON_RAILS_VERBOSE"] == "true"
+
+    if verbose
+      puts Rainbow("🚀 Starting React on Rails pack generation...").bold
+      puts Rainbow("📁 Auto-load bundle: #{ReactOnRails.configuration.auto_load_bundle}").cyan
+      puts Rainbow("📂 Components subdirectory: #{ReactOnRails.configuration.components_subdirectory}").cyan
+      puts ""
+    end
 
     begin
       start_time = Time.now
       ReactOnRails::PacksGenerator.instance.generate_packs_if_stale
       end_time = Time.now
 
-      puts ""
-      puts Rainbow("✨ Pack generation completed in #{((end_time - start_time) * 1000).round(1)}ms").green
+      if verbose
+        puts ""
+        puts Rainbow("✨ Pack generation completed in #{((end_time - start_time) * 1000).round(1)}ms").green
+      end
     rescue ReactOnRails::Error => e
       handle_react_on_rails_error(e)
       exit 1

spec/react_on_rails/dev/pack_generator_spec.rb

@@ -104,6 +104,43 @@
         expect(error_output.join("\n")).to match(/Error generating packs: Task failed/)
       end
 
+      it "suggests --verbose flag when pack generation fails in quiet mode" do
+        allow(mock_task).to receive(:invoke).and_raise(StandardError.new("Task failed"))
+
+        # Mock STDERR.puts to suppress error output
+        # rubocop:disable Style/GlobalStdStream
+        allow(STDERR).to receive(:puts)
+        # rubocop:enable Style/GlobalStdStream
+
+        expect { described_class.generate(verbose: false) }
+          .to output(/Run with.*--verbose.*flag for detailed output/).to_stdout_from_any_process
+          .and raise_error(SystemExit)
+      end
+
+      it "does not suggest --verbose flag when already in verbose mode" do
+        allow(mock_task).to receive(:invoke).and_raise(StandardError.new("Task failed"))
+
+        # Mock STDERR.puts to suppress error output
+        # rubocop:disable Style/GlobalStdStream
+        allow(STDERR).to receive(:puts)
+        # rubocop:enable Style/GlobalStdStream
+
+        # Capture output to verify --verbose suggestion is not shown
+        output = StringIO.new
+        # rubocop:disable RSpec/ExpectOutput
+        begin
+          $stdout = output
+          described_class.generate(verbose: true)
+        rescue SystemExit
+          # Expected to exit
+        ensure
+          $stdout = STDOUT
+        end
+        # rubocop:enable RSpec/ExpectOutput
+
+        expect(output.string).not_to match(/Run with.*--verbose/)
+      end
+
       it "outputs errors to stderr even in silent mode" do
         allow(mock_task).to receive(:invoke).and_raise(StandardError.new("Silent mode error"))