feat(compiler): add .rb file support with rbs prototype

- Copy .rb files from src to build directory
- Generate .rbs signatures using 'rbs prototype rb'
- Update watcher to monitor both .trb and .rb files
- Bump version to 0.0.10

Author: yhk1038

lib/t_ruby/cli.rb

@@ -7,6 +7,7 @@ class CLI
 
       Usage:
         trc <file.trb>           Compile a .trb file to .rb
+        trc <file.rb>            Copy .rb file to build/ and generate .rbs
         trc --init               Initialize a new t-ruby project
         trc --watch, -w          Watch input files and recompile on change
         trc --decl <file.trb>    Generate .d.trb declaration file
@@ -16,9 +17,10 @@ class CLI
 
       Examples:
         trc hello.trb            Compile hello.trb to build/hello.rb
+        trc utils.rb             Copy utils.rb to build/ and generate utils.rbs
         trc --init               Create trbconfig.yml and src/, build/ directories
-        trc -w                   Watch all .trb files in current directory
-        trc -w src/              Watch all .trb files in src/ directory
+        trc -w                   Watch all .trb and .rb files in current directory
+        trc -w src/              Watch all .trb and .rb files in src/ directory
         trc --watch hello.trb    Watch specific file for changes
         trc --decl hello.trb     Generate hello.d.trb declaration file
         trc --lsp                Start language server for VS Code

lib/t_ruby/compiler.rb

@@ -20,8 +20,13 @@ def compile(input_path)
         raise ArgumentError, "File not found: #{input_path}"
       end
 
+      # Handle .rb files separately
+      if input_path.end_with?(".rb")
+        return copy_ruby_file(input_path)
+      end
+
       unless input_path.end_with?(".trb")
-        raise ArgumentError, "Expected .trb file, got: #{input_path}"
+        raise ArgumentError, "Expected .trb or .rb file, got: #{input_path}"
       end
 
       source = File.read(input_path)
@@ -214,6 +219,36 @@ def generate_dtrb_file(input_path, out_dir)
       generator = DeclarationGenerator.new
       generator.generate_file(input_path, out_dir)
     end
+
+    # Copy .rb file to output directory and generate .rbs signature
+    def copy_ruby_file(input_path)
+      unless File.exist?(input_path)
+        raise ArgumentError, "File not found: #{input_path}"
+      end
+
+      out_dir = @config.out_dir
+      FileUtils.mkdir_p(out_dir)
+
+      base_filename = File.basename(input_path, ".rb")
+      output_path = File.join(out_dir, base_filename + ".rb")
+
+      # Copy the .rb file to output directory
+      FileUtils.cp(input_path, output_path)
+
+      # Generate .rbs file if enabled in config
+      if @config.emit["rbs"]
+        generate_rbs_from_ruby(base_filename, out_dir, input_path)
+      end
+
+      output_path
+    end
+
+    # Generate RBS from Ruby file using rbs prototype
+    def generate_rbs_from_ruby(base_filename, out_dir, input_path)
+      rbs_path = File.join(out_dir, base_filename + ".rbs")
+      result = `rbs prototype rb #{input_path} 2>/dev/null`
+      File.write(rbs_path, result) unless result.strip.empty?
+    end
   end
 
   # IR-aware code generator for source-preserving transformation

lib/t_ruby/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module TRuby
-  VERSION = "0.0.9"
+  VERSION = "0.0.10"
 end

lib/t_ruby/watcher.rb

@@ -59,8 +59,8 @@ def watch
       compile_all
       @stats[:total_time] += Time.now - start_time
 
-      # Start watching
-      listener = Listen.to(*watch_directories, only: /\.trb$/) do |modified, added, removed|
+      # Start watching (.trb and .rb files)
+      listener = Listen.to(*watch_directories, only: /\.(trb|rb)$/) do |modified, added, removed|
         handle_changes(modified, added, removed)
       end
 
@@ -91,7 +91,7 @@ def watch_directories
     end
 
     def handle_changes(modified, added, removed)
-      changed_files = (modified + added).select { |f| f.end_with?(".trb") }
+      changed_files = (modified + added).select { |f| f.end_with?(".trb") || f.end_with?(".rb") }
       return if changed_files.empty? && removed.empty?
 
       puts
@@ -120,25 +120,33 @@ def compile_all
       errors = []
 
       trb_files = find_trb_files
-      @file_count = trb_files.size
+      rb_files = find_rb_files
+      all_files = trb_files + rb_files
+      @file_count = all_files.size
 
       if @incremental && @cross_file_check
         # Use enhanced incremental compiler with cross-file checking
         result = @incremental_compiler.compile_all_with_checking(trb_files)
         errors = result[:errors].map { |e| format_error(e[:file], e[:error] || e[:message]) }
         @error_count = errors.size
         @stats[:total_compilations] += trb_files.size
-      elsif @parallel && trb_files.size > 1
+
+        # Also compile .rb files
+        rb_files.each do |file|
+          result = compile_file(file)
+          errors.concat(result[:errors]) if result[:errors].any?
+        end
+      elsif @parallel && all_files.size > 1
         # Parallel compilation
-        results = @parallel_processor.process_files(trb_files) do |file|
+        results = @parallel_processor.process_files(all_files) do |file|
           compile_file(file)
         end
         results.each do |result|
           errors.concat(result[:errors]) if result[:errors]&.any?
         end
       else
         # Sequential compilation
-        trb_files.each do |file|
+        all_files.each do |file|
           result = compile_file(file)
           errors.concat(result[:errors]) if result[:errors].any?
         end
@@ -234,6 +242,18 @@ def find_trb_files
       files.uniq
     end
 
+    def find_rb_files
+      files = []
+      @paths.each do |path|
+        if File.directory?(path)
+          files.concat(Dir.glob(File.join(path, "**", "*.rb")))
+        elsif File.file?(path) && path.end_with?(".rb")
+          files << path
+        end
+      end
+      files.uniq
+    end
+
     def format_error(file, message)
       # Parse error message for line/column info if available
       # Format: file:line:col - error TRB0001: message

spec/t_ruby/cli_spec.rb

@@ -150,7 +150,7 @@
     end
 
     context "with wrong file extension" do
-      it "displays error message for .rb file" do
+      it "compiles .rb file successfully (copies to build and generates rbs)" do
         Dir.mktmpdir do |tmpdir|
           input_file = File.join(tmpdir, "test.rb")
           File.write(input_file, "puts 'hello'")
@@ -159,7 +159,7 @@
 
           expect {
             cli.run
-          }.to raise_error(SystemExit)
+          }.to output(/Compiled: .* -> /).to_stdout
         end
       end