Implement FFI console mode support

Rakefile

@@ -25,11 +25,13 @@ task ffi_version_file => "#{name.tr('/', '-')}.gemspec" do |t|
 end
 
 task :build => ffi_version_file
+task :test => ffi_version_file if RUBY_ENGINE == "jruby"
 
 Rake::TestTask.new(:test) do |t|
   if extask
     t.libs = [extask.lib_dir.chomp("/"+File.dirname(name))]
   end
+  t.libs.unshift "lib/ffi" if RUBY_ENGINE == "jruby"
   t.libs << "test/lib"
   t.ruby_opts << "-rhelper"
   t.options = "--ignore-name=TestIO_Console#test_bad_keyword" if RUBY_ENGINE == "jruby"

lib/ffi/io/console/bsd_console.rb

@@ -6,8 +6,6 @@
   raise LoadError.new("native console on MacOS only supported on #{tested_platforms.join(', ')}")
 end
 
-require_relative 'native_console'
-
 module IO::LibC
   extend FFI::Library
   ffi_lib FFI::Library::LIBC
@@ -172,3 +170,5 @@ class Winsize < FFI::Struct
   attach_function :tcflush, [ :int, :int ], :int
   attach_function :ioctl, [ :int, :ulong, :varargs ], :int
 end
+
+require_relative 'native_console'

lib/ffi/io/console/linux_console.rb

@@ -6,8 +6,6 @@
   warn "native console only tested on #{tested_platforms.join(', ')}"
 end
 
-require_relative 'native_console'
-
 module IO::LibC
   extend FFI::Library
   ffi_lib FFI::Library::LIBC
@@ -204,3 +202,5 @@ class Winsize < FFI::Struct
   attach_function :tcflush, [ :int, :int ], :int
   attach_function :ioctl, [ :int, :ulong, :varargs ], :int
 end
+
+require_relative 'native_console'

lib/ffi/io/console/native_console.rb

@@ -8,21 +8,26 @@ def ttymode
 
     if block_given?
       yield tmp = termios.dup
-      if LibC.tcsetattr(self.fileno, LibC::TCSANOW, tmp) != 0
-        raise SystemCallError.new(respond_to?(:path) ? path : "tcsetattr(TCSANOW)", FFI.errno)
-      end
+      ttymode_set(tmp)
     end
     termios
   end
   private :ttymode
 
+  def ttymode_set(termios)
+    if LibC.tcsetattr(self.fileno, LibC::TCSANOW, termios) != 0
+      raise SystemCallError.new(respond_to?(:path) ? path : "tcsetattr(TCSANOW)", FFI.errno)
+    end
+  end
+  private :ttymode_set
+
   def ttymode_yield(block, **opts, &setup)
     begin
       orig_termios = ttymode { |t| setup.call(t, **opts) }
       block.call(self)
     ensure
-      if orig_termios && LibC.tcsetattr(self.fileno, LibC::TCSANOW, orig_termios) != 0
-        raise SystemCallError.new(respond_to?(:path) ? path : "tcsetattr(TCSANOW)", FFI.errno)
+      if orig_termios
+        ttymode_set(orig_termios)
       end
     end
   end
@@ -83,6 +88,46 @@ def noecho(&block)
     ttymode_yield(block) { |t| t[:c_lflag] &= ~(TTY_ECHO) }
   end
 
+  class ConsoleMode
+    attr_reader :termios
+
+    def initialize(t)
+      @termios = t
+    end
+
+    def initialize_copy(m)
+      @termios = m.termios.dup
+    end
+
+    def echo=(echo)
+      if echo
+        @termios[:c_lflag] |= TTY_ECHO
+      else
+        @termios[:c_lflag] &= ~TTY_ECHO
+      end
+    end
+
+    def raw!(min: 1, time: nil, intr: nil)
+      TTY_RAW[@termios, min:, time:, intr:]
+      self
+    end
+
+    def raw(min: 1, time: nil, intr: nil)
+      new_mode = dup
+      TTY_RAW[new_mode.termios, min:, time:, intr:]
+      new_mode
+    end
+  end
+
+  def console_mode
+    ConsoleMode.new(ttymode)
+  end
+
+  def console_mode=(mode)
+    ttymode_set(mode.termios)
+    mode
+  end
+
   def winsize
     ws = LibC::Winsize.new
     if LibC.ioctl(self.fileno, LibC::TIOCGWINSZ, :pointer, ws.pointer) != 0

test/io/console/test_io_console.rb

@@ -270,6 +270,29 @@ def test_setecho2
     }
   end
 
+  def test_console_mode
+    helper {|m, s|
+      begin
+        original = s.console_mode
+        assert_kind_of(IO::ConsoleMode, original)
+
+        noecho = original.dup
+        noecho.echo = false
+        assert_same(noecho, s.send(:console_mode=, noecho))
+        assert_not_predicate(s, :echo?)
+
+        raw = original.raw
+        assert_not_same(original, raw)
+        assert_same(raw, raw.raw!)
+        assert_same(raw, s.send(:console_mode=, raw))
+        s.print "raw\n"
+        assert_equal("raw\n", m.gets)
+      ensure
+        s.console_mode = original if original
+      end
+    }
+  end
+
   def test_tty_on_pty
     pend "not supported" unless TTY_ENHANCED