Fix for invalid subcommand

Author: mrkn

lib/iruby/application.rb

@@ -4,6 +4,7 @@
 require "rbconfig"
 require "singleton"
 
+require_relative "error"
 require_relative "kernel_app"
 
 module IRuby
@@ -56,7 +57,13 @@ def setup(argv=nil)
         argv = ["console", *argv]
       end
 
-      parse_sub_command(argv) if argv.length > 0
+      begin
+        parse_sub_command(argv) if argv.length > 0
+      rescue InvalidSubcommandError => err
+        $stderr.puts err.message
+        print_help(opts, $stderr)
+        abort
+      end
     end
 
     SUB_COMMANDS = {
@@ -75,17 +82,15 @@ def setup(argv=nil)
         @sub_cmd = sub_cmd.to_sym
         @sub_argv = sub_argv
       else
-        $stderr.puts "Invalid sub-command name: #{sub_cmd}"
-        print_help(opts, $stderr)
-        abort
+        raise InvalidSubcommandError.new(sub_cmd, sub_argv)
       end
     end
 
     private def print_help(opts, out=$stdout)
       out.puts opts.help
       out.puts
-      out.puts "Sub-commands"
-      out.puts "============"
+      out.puts "Subcommands"
+      out.puts "==========="
       SUB_COMMANDS.each do |name, description|
         out.puts "#{name}"
         out.puts "    #{description}"

lib/iruby/error.rb

@@ -0,0 +1,12 @@
+module IRuby
+  class Error < StandardError
+  end
+
+  class InvalidSubcommandError < Error
+    def initialize(name, argv)
+      @name = name
+      @argv = argv
+      super("Invalid subcommand name: #{@name}")
+    end
+  end
+end

test/iruby/application/application_test.rb

@@ -21,5 +21,12 @@ def test_version
       assert status.success?
       assert_match(/\bIRuby\s+#{Regexp.escape(IRuby::VERSION)}\b/, out)
     end
+
+    def test_unknown_subcommand
+      out, status = Open3.capture2e(*iruby_command("matz"))
+      refute status.success?
+      assert_match(/^Invalid subcommand name: matz$/, out)
+      assert_match(/^Subcommands$/, out)
+    end
   end
 end