ruby--ruby/test/ruby/test_io_m17n.rb

require 'test/unit'
require 'tmpdir'
require 'timeout'
require_relative 'envutil'

class TestIO_M17N < Test::Unit::TestCase
  ENCS = [
    Encoding::ASCII_8BIT,
    Encoding::EUC_JP,
    Encoding::Shift_JIS,
    Encoding::UTF_8
  ]

  def with_tmpdir
    Dir.mktmpdir {|dir|
      Dir.chdir(dir) {
        yield dir
      }
    }
  end

  def with_pipe(*args)
    r, w = IO.pipe(*args)
    begin
      yield r, w
    ensure
      r.close if !r.closed?
      w.close if !w.closed?
    end
  end

  def generate_file(path, content)
    open(path, "wb") {|f| f.write content }
  end

  def encdump(str)
    "#{str.dump}.force_encoding(#{str.encoding.name.dump})"
  end

  def assert_str_equal(expected, actual, message=nil)
    full_message = build_message(message, <<EOT)
#{encdump expected} expected but not equal to
#{encdump actual}.
EOT
    assert_block(full_message) { expected == actual }
  end

  def test_open_r
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "r") {|f|
        assert_equal(Encoding.default_external, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_rb
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "rb") {|f|
        assert_equal(Encoding.default_external, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_r_enc
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "r:euc-jp") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_r_enc_in_opt
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "r", encoding: "euc-jp") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_r_enc_in_opt2
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "r", external_encoding: "euc-jp") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_r_enc_enc
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "r:euc-jp:utf-8") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
      }
    }
  end

  def test_open_r_enc_enc_in_opt
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "r", encoding: "euc-jp:utf-8") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
      }
    }
  end

  def test_open_r_enc_enc_in_opt2
    with_tmpdir {
      generate_file('tmp', "")
      open("tmp", "r", external_encoding: "euc-jp", internal_encoding: "utf-8") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
      }
    }
  end

  def test_open_w
    with_tmpdir {
      open("tmp", "w") {|f|
        assert_equal(nil, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_wb
    with_tmpdir {
      open("tmp", "wb") {|f|
        assert_equal(nil, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_w_enc
    with_tmpdir {
      open("tmp", "w:euc-jp") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_w_enc_in_opt
    with_tmpdir {
      open("tmp", "w", encoding: "euc-jp") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_w_enc_in_opt2
    with_tmpdir {
      open("tmp", "w", external_encoding: "euc-jp") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
      }
    }
  end

  def test_open_w_enc_enc
    with_tmpdir {
      open("tmp", "w:euc-jp:utf-8") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
      }
    }
  end

  def test_open_w_enc_enc_in_opt
    with_tmpdir {
      open("tmp", "w", encoding: "euc-jp:utf-8") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
      }
    }
  end

  def test_open_w_enc_enc_in_opt2
    with_tmpdir {
      open("tmp", "w", external_encoding: "euc-jp", internal_encoding: "utf-8") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
      }
    }
  end

  def test_open_w_enc_enc_perm
    with_tmpdir {
      open("tmp", "w:euc-jp:utf-8", 0600) {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
      }
    }
  end

  def test_io_new_enc
    with_tmpdir {
      generate_file("tmp", "\xa1")
      fd = IO.sysopen("tmp")
      f = IO.new(fd, "r:sjis")
      begin
        assert_equal(Encoding::Shift_JIS, f.read.encoding)
      ensure
        f.close
      end
    }
  end

  def test_s_pipe_invalid
    r, w = IO.pipe("utf-8", "euc-jp", :invalid=>:replace)
    w << "\x80"
    w.close
    assert_equal("?", r.read)
  ensure
    r.close if r && !r.closed?
    w.close if w && !w.closed?
  end

  def test_s_pipe_undef
    r, w = IO.pipe("utf-8:euc-jp", :undef=>:replace)
    w << "\ufffd"
    w.close
    assert_equal("?", r.read)
  ensure
    r.close if r && !r.closed?
    w.close if w && !w.closed?
  end

  def test_s_pipe_undef_replace_string
    r, w = IO.pipe("utf-8:euc-jp", :undef=>:replace, :replace=>"X")
    w << "\ufffd"
    w.close
    assert_equal("X", r.read)
  ensure
    r.close if r && !r.closed?
    w.close if w && !w.closed?
  end

  def test_dup
    with_pipe("utf-8:euc-jp") {|r, w|
      w << "\u3042"
      w.close
      r2 = r.dup
      begin
        assert_equal("\xA4\xA2".force_encoding("euc-jp"), r2.read)
      ensure
        r2.close
      end

    }
  end

  def test_dup_undef
    with_pipe("utf-8:euc-jp", :undef=>:replace) {|r, w|
      w << "\uFFFD"
      w.close
      r2 = r.dup
      begin
        assert_equal("?", r2.read)
      ensure
        r2.close
      end
    }
  end

  def test_stdin
    assert_equal(Encoding.default_external, STDIN.external_encoding)
    assert_equal(nil, STDIN.internal_encoding)
  end

  def test_stdout
    assert_equal(nil, STDOUT.external_encoding)
    assert_equal(nil, STDOUT.internal_encoding)
  end

  def test_stderr
    assert_equal(nil, STDERR.external_encoding)
    assert_equal(nil, STDERR.internal_encoding)
  end

  def test_terminator_conversion
    with_tmpdir {
      generate_file('tmp', "before \u00FF after")
      s = open("tmp", "r:utf-8:iso-8859-1") {|f|
        f.gets("\xFF".force_encoding("iso-8859-1"))
      }
      assert_equal(Encoding.find("iso-8859-1"), s.encoding)
      assert_str_equal("before \xFF".force_encoding("iso-8859-1"), s, '[ruby-core:14288]')
    }
  end

  def test_terminator_conversion2
    with_tmpdir {
      generate_file('tmp', "before \xA1\xA2\xA2\xA3 after")
      s = open("tmp", "r:euc-jp:utf-8") {|f|
        f.gets("\xA2\xA2".force_encoding("euc-jp").encode("utf-8"))
      }
      assert_equal(Encoding.find("utf-8"), s.encoding)
      assert_str_equal("before \xA1\xA2\xA2\xA3 after".force_encoding("euc-jp").encode("utf-8"), s, '[ruby-core:14319]')
    }
  end

  def test_terminator_stateful_conversion
    with_tmpdir {
      src = "before \e$B\x23\x30\x23\x31\e(B after".force_encoding("iso-2022-jp")
      generate_file('tmp', src)
      s = open("tmp", "r:iso-2022-jp:euc-jp") {|f|
        f.gets("0".force_encoding("euc-jp"))
      }
      assert_equal(Encoding.find("euc-jp"), s.encoding)
      assert_str_equal(src.encode("euc-jp"), s)
    }
  end

  def test_nonascii_terminator
    with_tmpdir {
      generate_file('tmp', "before \xA2\xA2 after")
      open("tmp", "r:euc-jp") {|f|
        assert_raise(ArgumentError) {
          f.gets("\xA2\xA2".force_encoding("utf-8"))
        }
      }
    }
  end

  def test_pipe_terminator_conversion
    with_pipe("euc-jp:utf-8") {|r, w|
      w.write "before \xa2\xa2 after"
      rs = "\xA2\xA2".encode("utf-8", "euc-jp")
      w.close
      timeout(1) {
        assert_equal("before \xa2\xa2".encode("utf-8", "euc-jp"),
                     r.gets(rs))
      }
    }
  end

  def test_pipe_conversion
    with_pipe("euc-jp:utf-8") {|r, w|
      w.write "\xa1\xa1"
      assert_equal("\xa1\xa1".encode("utf-8", "euc-jp"), r.getc)
    }
  end

  def test_pipe_convert_partial_read
    with_pipe("euc-jp:utf-8") {|r, w|
      begin
        t = Thread.new {
          w.write "\xa1"
          sleep 0.1
          w.write "\xa1"
        }
        assert_equal("\xa1\xa1".encode("utf-8", "euc-jp"), r.getc)
      ensure
        t.join if t
      end
    }
  end

  def test_getc_invalid
    with_pipe("euc-jp:utf-8") {|r, w|
      w << "\xa1xyz"
      w.close
      err = assert_raise(Encoding::InvalidByteSequence) { r.getc }
      assert_equal("\xA1".force_encoding("ascii-8bit"), err.error_bytes)
      assert_equal("xyz", r.read(10))
    }
  end

  def test_getc_stateful_conversion
    with_tmpdir {
      src = "\e$B\x23\x30\x23\x31\e(B".force_encoding("iso-2022-jp")
      generate_file('tmp', src)
      open("tmp", "r:iso-2022-jp:euc-jp") {|f|
        assert_equal("\xa3\xb0".force_encoding("euc-jp"), f.getc)
        assert_equal("\xa3\xb1".force_encoding("euc-jp"), f.getc)
      }
    }
  end

  def test_ungetc_stateful_conversion
    with_tmpdir {
      src = "before \e$B\x23\x30\x23\x31\e(B after".force_encoding("iso-2022-jp")
      generate_file('tmp', src)
      s = open("tmp", "r:iso-2022-jp:euc-jp") {|f|
        f.ungetc("0".force_encoding("euc-jp"))
        f.read
      }
      assert_equal(Encoding.find("euc-jp"), s.encoding)
      assert_str_equal("0" + src.encode("euc-jp"), s)
    }
  end

  def test_ungetc_stateful_conversion2
    with_tmpdir {
      src =    "before \e$B\x23\x30\x23\x31\e(B after".force_encoding("iso-2022-jp")
      former = "before \e$B\x23\x30\e(B".force_encoding("iso-2022-jp")
      rs =            "\e$B\x23\x30\e(B".force_encoding("iso-2022-jp")
      latter =                "\e$B\x23\x31\e(B after".force_encoding("iso-2022-jp")
      generate_file('tmp', src)
      s = open("tmp", "r:iso-2022-jp:euc-jp") {|f|
        assert_equal(former.encode("euc-jp", "iso-2022-jp"),
                     f.gets(rs.encode("euc-jp", "iso-2022-jp")))
        f.ungetc("0")
        f.read
      }
      assert_equal(Encoding.find("euc-jp"), s.encoding)
      assert_str_equal("0" + latter.encode("euc-jp"), s)
    }
  end

  def test_open_ascii
    with_tmpdir {
      src = "abc\n"
      generate_file('tmp', "abc\n")
      ENCS.each {|enc|
        s = open('tmp', "r:#{enc}") {|f| f.gets }
        assert_equal(enc, s.encoding)
        assert_str_equal(src, s)
      }
    }
  end

  def test_open_nonascii
    with_tmpdir {
      src = "\xc2\xa1\n"
      generate_file('tmp', src)
      ENCS.each {|enc|
        content = src.dup.force_encoding(enc)
        s = open('tmp', "r:#{enc}") {|f| f.gets }
        assert_equal(enc, s.encoding)
        assert_str_equal(content, s)
      }
    }
  end

  def test_read_encoding
    with_tmpdir {
      src = "\xc2\xa1\n".force_encoding("ASCII-8BIT")
      generate_file('tmp', "\xc2\xa1\n")
      ENCS.each {|enc|
        content = src.dup.force_encoding(enc)
        open('tmp', "r:#{enc}") {|f|
          s = f.getc
          assert_equal(enc, s.encoding)
          assert_str_equal(content[0], s)
        }
        open('tmp', "r:#{enc}") {|f|
          s = f.readchar
          assert_equal(enc, s.encoding)
          assert_str_equal(content[0], s)
        }
        open('tmp', "r:#{enc}") {|f|
          s = f.gets
          assert_equal(enc, s.encoding)
          assert_str_equal(content, s)
        }
        open('tmp', "r:#{enc}") {|f|
          s = f.readline
          assert_equal(enc, s.encoding)
          assert_str_equal(content, s)
        }
        open('tmp', "r:#{enc}") {|f|
          lines = f.readlines
          assert_equal(1, lines.length)
          s = lines[0]
          assert_equal(enc, s.encoding)
          assert_str_equal(content, s)
        }
        open('tmp', "r:#{enc}") {|f|
          f.each_line {|s|
            assert_equal(enc, s.encoding)
            assert_str_equal(content, s)
          }
        }
        open('tmp', "r:#{enc}") {|f|
          s = f.read
          assert_equal(enc, s.encoding)
          assert_str_equal(content, s)
        }
        open('tmp', "r:#{enc}") {|f|
          s = f.read(1)
          assert_equal(Encoding::ASCII_8BIT, s.encoding)
          assert_str_equal(src[0], s)
        }
        open('tmp', "r:#{enc}") {|f|
          s = f.readpartial(1)
          assert_equal(Encoding::ASCII_8BIT, s.encoding)
          assert_str_equal(src[0], s)
        }
        open('tmp', "r:#{enc}") {|f|
          s = f.sysread(1)
          assert_equal(Encoding::ASCII_8BIT, s.encoding)
          assert_str_equal(src[0], s)
        }
      }
    }
  end

  def test_write_noenc
    src = "\xc2\xa1\n".force_encoding("ascii-8bit")
    with_tmpdir {
      open('tmp', "w") {|f|
        ENCS.each {|enc|
          f.write src.dup.force_encoding(enc)
        }
      }
      open('tmp', 'r:ascii-8bit') {|f|
        assert_equal(src*ENCS.length, f.read)
      }
    }
  end

  def test_write_conversion
    utf8 = "\u6666"
    eucjp = "\xb3\xa2".force_encoding("EUC-JP")
    with_tmpdir {
      open('tmp', "w:EUC-JP") {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(nil, f.internal_encoding)
        f.print utf8
      }
      assert_equal(eucjp, File.read('tmp').force_encoding("EUC-JP"))
      open('tmp', 'r:EUC-JP:UTF-8') {|f|
        assert_equal(Encoding::EUC_JP, f.external_encoding)
        assert_equal(Encoding::UTF_8, f.internal_encoding)
        assert_equal(utf8, f.read)
      }
    }
  end

  def test_pipe
    utf8 = "\u6666"
    eucjp = "\xb3\xa2".force_encoding("EUC-JP")

    with_pipe {|r,w|
      assert_equal(Encoding.default_external, r.external_encoding)
      assert_equal(nil, r.internal_encoding)
      w << utf8
      w.close
      s = r.read
      assert_equal(Encoding.default_external, s.encoding)
      assert_str_equal(utf8.dup.force_encoding(Encoding.default_external), s)
    }

    with_pipe("EUC-JP") {|r,w|
      assert_equal(Encoding::EUC_JP, r.external_encoding)
      assert_equal(nil, r.internal_encoding)
      w << eucjp
      w.close
      assert_equal(eucjp, r.read)
    }

    with_pipe("UTF-8:EUC-JP") {|r,w|
      assert_equal(Encoding::UTF_8, r.external_encoding)
      assert_equal(Encoding::EUC_JP, r.internal_encoding)
      w << utf8
      w.close
      assert_equal(eucjp, r.read)
    }

    ENCS.each {|enc|
      with_pipe(enc) {|r, w|
        w << "\xc2\xa1"
        w.close
        s = r.getc 
        assert_equal(enc, s.encoding)
      }
    }

    ENCS.each {|enc|
      next if enc == Encoding::ASCII_8BIT
      next if enc == Encoding::UTF_8
      with_pipe("#{enc}:UTF-8") {|r, w|
        w << "\xc2\xa1"
        w.close
        s = r.read
        assert_equal(Encoding::UTF_8, s.encoding)
        assert_equal(s.encode("UTF-8"), s)
      }
    }

  end

  def test_marshal
    with_pipe("EUC-JP") {|r, w|
      data = 56225
      Marshal.dump(data, w)
      w.close
      result = nil
      assert_nothing_raised("[ruby-dev:33264]") { result = Marshal.load(r) }
      assert_equal(data, result)
    }
  end

  def test_gets_nil
    with_pipe("UTF-8:EUC-JP") {|r, w|
      w << "\u{3042}"
      w.close
      result = r.gets(nil)
      assert_equal("\u{3042}".encode("euc-jp"), result)
    }
  end

  def test_gets_limit
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.gets(1))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.gets(2))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2\xa4\xa4".force_encoding("euc-jp"), r.gets(3))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2\xa4\xa4".force_encoding("euc-jp"), r.gets(4))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2\xa4\xa4\xa4\xa6".force_encoding("euc-jp"), r.gets(5))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2\xa4\xa4\xa4\xa6".force_encoding("euc-jp"), r.gets(6))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2\xa4\xa4\xa4\xa6\n".force_encoding("euc-jp"), r.gets(7))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2\xa4\xa4\xa4\xa6\n".force_encoding("euc-jp"), r.gets(8))
    }
    with_pipe("euc-jp") {|r, w| w << "\xa4\xa2\xa4\xa4\xa4\xa6\n\xa4\xa8\xa4\xaa"; w.close
      assert_equal("\xa4\xa2\xa4\xa4\xa4\xa6\n".force_encoding("euc-jp"), r.gets(9))
    }
  end

  def test_gets_invalid
    with_pipe("utf-8:euc-jp") {|r, w|
      before = "\u{3042}\u{3044}"
      invalid = "\x80".force_encoding("utf-8")
      after = "\u{3046}\u{3048}"
      w << before + invalid + after
      w.close
      err = assert_raise(Encoding::InvalidByteSequence) { r.gets }
      assert_equal(invalid.force_encoding("ascii-8bit"), err.error_bytes)
      assert_equal(after.encode("euc-jp"), r.gets)
    }
  end

  def test_getc_invalid2
    with_pipe("utf-8:euc-jp") {|r, w|
      before1 = "\u{3042}"
      before2 = "\u{3044}"
      invalid = "\x80".force_encoding("utf-8")
      after1 = "\u{3046}"
      after2 = "\u{3048}"
      w << before1 + before2 + invalid + after1 + after2
      w.close
      assert_equal(before1.encode("euc-jp"), r.getc)
      assert_equal(before2.encode("euc-jp"), r.getc)
      err = assert_raise(Encoding::InvalidByteSequence) { r.getc }
      assert_equal(invalid.force_encoding("ascii-8bit"), err.error_bytes)
      assert_equal(after1.encode("euc-jp"), r.getc)
      assert_equal(after2.encode("euc-jp"), r.getc)
    }
  end

  def test_getc_invalid3
    with_pipe("utf-16le:euc-jp") {|r, w|
      before1 = "\x42\x30".force_encoding("utf-16le")
      before2 = "\x44\x30".force_encoding("utf-16le")
      invalid = "\x00\xd8".force_encoding("utf-16le")
      after1 = "\x46\x30".force_encoding("utf-16le")
      after2 = "\x48\x30".force_encoding("utf-16le")
      w << before1 + before2 + invalid + after1 + after2
      w.close
      assert_equal(before1.encode("euc-jp"), r.getc)
      assert_equal(before2.encode("euc-jp"), r.getc)
      err = assert_raise(Encoding::InvalidByteSequence) { r.getc }
      assert_equal(invalid.force_encoding("ascii-8bit"), err.error_bytes)
      assert_equal(after1.encode("euc-jp"), r.getc)
      assert_equal(after2.encode("euc-jp"), r.getc)
    }
  end

  def test_read_all
    with_pipe("utf-8:euc-jp") {|r, w|
      str = "\u3042\u3044"
      w << str
      w.close
      assert_equal(str.encode("euc-jp"), r.read)
    }
  end

  def test_read_all_invalid
    with_pipe("utf-8:euc-jp") {|r, w|
      before = "\u{3042}\u{3044}"
      invalid = "\x80".force_encoding("utf-8")
      after = "\u{3046}\u{3048}"
      w << before + invalid + after
      w.close
      err = assert_raise(Encoding::InvalidByteSequence) { r.read }
      assert_equal(invalid.force_encoding("ascii-8bit"), err.error_bytes)
      assert_equal(after.encode("euc-jp"), r.read)
    }
  end

  def test_file_foreach
    with_tmpdir {
      generate_file('tst', 'a' * 8191 + "\xa1\xa1")
      assert_nothing_raised {
        File.foreach('tst', :encoding=>"euc-jp") {|line| line.inspect }
      }
    }
  end

  def test_set_encoding
    with_pipe("utf-8:euc-jp") {|r, w|
      s = "\u3042".force_encoding("ascii-8bit")
      s << "\x82\xa0".force_encoding("ascii-8bit")
      w << s
      w.close
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.getc)
      r.set_encoding("shift_jis:euc-jp")
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.getc)
    }
  end

  def test_set_encoding2
    with_pipe("utf-8:euc-jp") {|r, w|
      s = "\u3042".force_encoding("ascii-8bit")
      s << "\x82\xa0".force_encoding("ascii-8bit")
      w << s
      w.close
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.getc)
      r.set_encoding("shift_jis", "euc-jp")
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.getc)
    }
  end

  def test_set_encoding_nil
    with_pipe("utf-8:euc-jp") {|r, w|
      s = "\u3042".force_encoding("ascii-8bit")
      s << "\x82\xa0".force_encoding("ascii-8bit")
      w << s
      w.close
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.getc)
      r.set_encoding(nil)
      assert_equal("\x82\xa0".force_encoding(Encoding.default_external), r.read)
    }
  end

  def test_set_encoding_enc
    with_pipe("utf-8:euc-jp") {|r, w|
      s = "\u3042".force_encoding("ascii-8bit")
      s << "\x82\xa0".force_encoding("ascii-8bit")
      w << s
      w.close
      assert_equal("\xa4\xa2".force_encoding("euc-jp"), r.getc)
      r.set_encoding(Encoding::Shift_JIS)
      assert_equal("\x82\xa0".force_encoding(Encoding::Shift_JIS), r.getc)
    }
  end

  def test_set_encoding_invalid
    with_pipe {|r, w|
      w << "\x80"
      w.close
      r.set_encoding("utf-8:euc-jp", :invalid=>:replace)
      assert_equal("?", r.read)
    }
  end

  def test_set_encoding_undef
    with_pipe {|r, w|
      w << "\ufffd"
      w.close
      r.set_encoding("utf-8", "euc-jp", :undef=>:replace)
      assert_equal("?", r.read)
    }
  end

  def test_write_conversion_fixenc
    with_pipe {|r, w|
      w.set_encoding("iso-2022-jp:utf-8")
      t = Thread.new { r.read.force_encoding("ascii-8bit") }
      w << "\u3042"
      w << "\u3044"
      w.close
      assert_equal("\e$B$\"$$\e(B".force_encoding("ascii-8bit"), t.value)
    }
  end

  def test_write_conversion_anyenc_stateful
    with_pipe {|r, w|
      w.set_encoding("iso-2022-jp")
      t = Thread.new { r.read.force_encoding("ascii-8bit") }
      w << "\u3042"
      w << "\x82\xa2".force_encoding("sjis")
      w.close
      assert_equal("\e$B$\"$$\e(B".force_encoding("ascii-8bit"), t.value)
    }
  end

  def test_write_conversion_anyenc_stateless
    with_pipe {|r, w|
      w.set_encoding("euc-jp")
      t = Thread.new { r.read.force_encoding("ascii-8bit") }
      w << "\u3042"
      w << "\x82\xa2".force_encoding("sjis")
      w.close
      assert_equal("\xa4\xa2\xa4\xa4".force_encoding("ascii-8bit"), t.value)
    }
  end

  def test_write_conversion_anyenc_stateful_nosync
    with_pipe {|r, w|
      w.sync = false
      w.set_encoding("iso-2022-jp")
      t = Thread.new { r.read.force_encoding("ascii-8bit") }
      w << "\u3042"
      w << "\x82\xa2".force_encoding("sjis")
      w.close
      assert_equal("\e$B$\"$$\e(B".force_encoding("ascii-8bit"), t.value)
    }
  end

  def test_read_stateful
    with_pipe("euc-jp:iso-2022-jp") {|r, w|
      w << "\xA4\xA2"
      w.close
      assert_equal("\e$B$\"\e(B".force_encoding("iso-2022-jp"), r.read)
    }
  end

  def test_stdin_external_encoding_with_reopen
    with_tmpdir {
      open("tst", "w+") {|f|
        pid = spawn(EnvUtil.rubybin, '-e', <<-'End', 10=>f)
          io = IO.new(10, "r+")
          STDIN.reopen(io)
          STDIN.external_encoding
          STDIN.write "\u3042"
          STDIN.flush 
        End
        Process.wait pid
        f.rewind
        result = f.read.force_encoding("ascii-8bit")
        assert_equal("\u3042".force_encoding("ascii-8bit"), result)
      }
    }
  end

  def test_popen_r_enc
    IO.popen("#{EnvUtil.rubybin} -e 'putc 255'", "r:ascii-8bit") {|f|
      assert_equal(Encoding::ASCII_8BIT, f.external_encoding)
      assert_equal(nil, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::ASCII_8BIT, s.encoding)
      assert_equal("\xff".force_encoding("ascii-8bit"), s)
    }
  end

  def test_popen_r_enc_in_opt
    IO.popen("#{EnvUtil.rubybin} -e 'putc 255'", "r", encoding: "ascii-8bit") {|f|
      assert_equal(Encoding::ASCII_8BIT, f.external_encoding)
      assert_equal(nil, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::ASCII_8BIT, s.encoding)
      assert_equal("\xff".force_encoding("ascii-8bit"), s)
    }
  end

  def test_popen_r_enc_in_opt2
    IO.popen("#{EnvUtil.rubybin} -e 'putc 255'", "r", external_encoding: "ascii-8bit") {|f|
      assert_equal(Encoding::ASCII_8BIT, f.external_encoding)
      assert_equal(nil, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::ASCII_8BIT, s.encoding)
      assert_equal("\xff".force_encoding("ascii-8bit"), s)
    }
  end

  def test_popen_r_enc_enc
    IO.popen("#{EnvUtil.rubybin} -e 'putc 0xa1'", "r:shift_jis:euc-jp") {|f|
      assert_equal(Encoding::Shift_JIS, f.external_encoding)
      assert_equal(Encoding::EUC_JP, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::EUC_JP, s.encoding)
      assert_equal("\x8e\xa1".force_encoding("euc-jp"), s)
    }
  end

  def test_popen_r_enc_enc_in_opt
    IO.popen("#{EnvUtil.rubybin} -e 'putc 0xa1'", "r", encoding: "shift_jis:euc-jp") {|f|
      assert_equal(Encoding::Shift_JIS, f.external_encoding)
      assert_equal(Encoding::EUC_JP, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::EUC_JP, s.encoding)
      assert_equal("\x8e\xa1".force_encoding("euc-jp"), s)
    }
  end

  def test_popen_r_enc_enc_in_opt2
    IO.popen("#{EnvUtil.rubybin} -e 'putc 0xa1'", "r", external_encoding: "shift_jis", internal_encoding: "euc-jp") {|f|
      assert_equal(Encoding::Shift_JIS, f.external_encoding)
      assert_equal(Encoding::EUC_JP, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::EUC_JP, s.encoding)
      assert_equal("\x8e\xa1".force_encoding("euc-jp"), s)
    }
  end

  def test_popenv_r_enc_enc_in_opt2
    IO.popen([EnvUtil.rubybin, "-e", "putc 0xa1"], "r", external_encoding: "shift_jis", internal_encoding: "euc-jp") {|f|
      assert_equal(Encoding::Shift_JIS, f.external_encoding)
      assert_equal(Encoding::EUC_JP, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::EUC_JP, s.encoding)
      assert_equal("\x8e\xa1".force_encoding("euc-jp"), s)
    }
  end

  def test_open_pipe_r_enc
    open("|#{EnvUtil.rubybin} -e 'putc 255'", "r:ascii-8bit") {|f|
      assert_equal(Encoding::ASCII_8BIT, f.external_encoding)
      assert_equal(nil, f.internal_encoding)
      s = f.read
      assert_equal(Encoding::ASCII_8BIT, s.encoding)
      assert_equal("\xff".force_encoding("ascii-8bit"), s)
    }
  end

  def test_s_foreach_enc
    with_tmpdir {
      generate_file("t", "\xff")
      IO.foreach("t", :mode => "r:ascii-8bit") {|s|
        assert_equal(Encoding::ASCII_8BIT, s.encoding)
        assert_equal("\xff".force_encoding("ascii-8bit"), s)
      }
    }
  end

  def test_s_foreach_enc_in_opt
    with_tmpdir {
      generate_file("t", "\xff")
      IO.foreach("t", :encoding => "ascii-8bit") {|s|
        assert_equal(Encoding::ASCII_8BIT, s.encoding)
        assert_equal("\xff".force_encoding("ascii-8bit"), s)
      }
    }
  end

  def test_s_foreach_enc_in_opt2
    with_tmpdir {
      generate_file("t", "\xff")
      IO.foreach("t", :external_encoding => "ascii-8bit") {|s|
        assert_equal(Encoding::ASCII_8BIT, s.encoding)
        assert_equal("\xff".force_encoding("ascii-8bit"), s)
      }
    }
  end

  def test_s_foreach_enc_enc
    with_tmpdir {
      generate_file("t", "\u3042")
      IO.foreach("t", :mode => "r:utf-8:euc-jp") {|s|
        assert_equal(Encoding::EUC_JP, s.encoding)
        assert_equal("\xa4\xa2".force_encoding("euc-jp"), s)
      }
    }
  end

  def test_s_foreach_enc_enc_in_opt
    with_tmpdir {
      generate_file("t", "\u3042")
      IO.foreach("t", :mode => "r", :encoding => "utf-8:euc-jp") {|s|
        assert_equal(Encoding::EUC_JP, s.encoding)
        assert_equal("\xa4\xa2".force_encoding("euc-jp"), s)
      }
    }
  end

  def test_s_foreach_enc_enc_in_opt2
    with_tmpdir {
      generate_file("t", "\u3042")
      IO.foreach("t", :mode => "r", :external_encoding => "utf-8", :internal_encoding => "euc-jp") {|s|
        assert_equal(Encoding::EUC_JP, s.encoding)
        assert_equal("\xa4\xa2".force_encoding("euc-jp"), s)
      }
    }
  end

  def test_s_foreach_open_args_enc
    with_tmpdir {
      generate_file("t", "\xff")
      IO.foreach("t", :open_args => ["r:ascii-8bit"]) {|s|
        assert_equal(Encoding::ASCII_8BIT, s.encoding)
        assert_equal("\xff".force_encoding("ascii-8bit"), s)
      }
    }
  end

  def test_s_foreach_open_args_enc_in_opt
    with_tmpdir {
      generate_file("t", "\xff")
      IO.foreach("t", :open_args => ["r", encoding: "ascii-8bit"]) {|s|
        assert_equal(Encoding::ASCII_8BIT, s.encoding)
        assert_equal("\xff".force_encoding("ascii-8bit"), s)
      }
    }
  end

  def test_s_foreach_open_args_enc_in_opt2
    with_tmpdir {
      generate_file("t", "\xff")
      IO.foreach("t", :open_args => ["r", external_encoding: "ascii-8bit"]) {|s|
        assert_equal(Encoding::ASCII_8BIT, s.encoding)
        assert_equal("\xff".force_encoding("ascii-8bit"), s)
      }
    }
  end

  def test_s_foreach_open_args_enc_enc
    with_tmpdir {
      generate_file("t", "\u3042")
      IO.foreach("t", :open_args => ["r:utf-8:euc-jp"]) {|s|
        assert_equal(Encoding::EUC_JP, s.encoding)
        assert_equal("\xa4\xa2".force_encoding("euc-jp"), s)
      }
    }
  end

  def test_s_foreach_open_args_enc_enc_in_opt
    with_tmpdir {
      generate_file("t", "\u3042")
      IO.foreach("t", :open_args => ["r", encoding: "utf-8:euc-jp"]) {|s|
        assert_equal(Encoding::EUC_JP, s.encoding)
        assert_equal("\xa4\xa2".force_encoding("euc-jp"), s)
      }
    }
  end

  def test_s_foreach_open_args_enc_enc_in_opt2
    with_tmpdir {
      generate_file("t", "\u3042")
      IO.foreach("t", :open_args => ["r", external_encoding: "utf-8", internal_encoding: "euc-jp"]) {|s|
        assert_equal(Encoding::EUC_JP, s.encoding)
        assert_equal("\xa4\xa2".force_encoding("euc-jp"), s)
      }
    }
  end

  def test_both_textmode_binmode
    assert_raise(ArgumentError) { open("not-exist", "r", :textmode=>true, :binmode=>true) }
  end

  def test_textmode_decode_universal_newline_read
    with_tmpdir {
      generate_file("t.crlf", "a\r\nb\r\nc\r\n")
      assert_equal("a\nb\nc\n", File.read("t.crlf", mode:"rt:euc-jp:utf-8"))
      assert_equal("a\nb\nc\n", File.read("t.crlf", mode:"rt"))
      open("t.crlf", "rt:euc-jp:utf-8") {|f| assert_equal("a\nb\nc\n", f.read) }
      open("t.crlf", "rt") {|f| assert_equal("a\nb\nc\n", f.read) }
      open("t.crlf", "r", :textmode=>true) {|f| assert_equal("a\nb\nc\n", f.read) }

      generate_file("t.cr", "a\rb\rc\r")
      assert_equal("a\nb\nc\n", File.read("t.cr", mode:"rt:euc-jp:utf-8"))
      assert_equal("a\nb\nc\n", File.read("t.cr", mode:"rt"))

      generate_file("t.lf", "a\nb\nc\n")
      assert_equal("a\nb\nc\n", File.read("t.cr", mode:"rt:euc-jp:utf-8"))
      assert_equal("a\nb\nc\n", File.read("t.cr", mode:"rt"))
    }
  end

  def test_textmode_decode_universal_newline_getc
    with_tmpdir {
      generate_file("t.crlf", "a\r\nb\r\nc\r\n")
      open("t.crlf", "rt") {|f|
        assert_equal("a", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("b", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("c", f.getc)
        assert_equal("\n", f.getc)
        assert_equal(nil, f.getc)
      }

      generate_file("t.cr", "a\rb\rc\r")
      open("t.cr", "rt") {|f|
        assert_equal("a", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("b", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("c", f.getc)
        assert_equal("\n", f.getc)
        assert_equal(nil, f.getc)
      }

      generate_file("t.lf", "a\nb\nc\n")
      open("t.lf", "rt") {|f|
        assert_equal("a", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("b", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("c", f.getc)
        assert_equal("\n", f.getc)
        assert_equal(nil, f.getc)
      }
    }
  end

  def test_textmode_decode_universal_newline_gets
    with_tmpdir {
      generate_file("t.crlf", "a\r\nb\r\nc\r\n")
      open("t.crlf", "rt") {|f|
        assert_equal("a\n", f.gets)
        assert_equal("b\n", f.gets)
        assert_equal("c\n", f.gets)
        assert_equal(nil, f.gets)
      }

      generate_file("t.cr", "a\rb\rc\r")
      open("t.cr", "rt") {|f|
        assert_equal("a\n", f.gets)
        assert_equal("b\n", f.gets)
        assert_equal("c\n", f.gets)
        assert_equal(nil, f.gets)
      }

      generate_file("t.lf", "a\nb\nc\n")
      open("t.lf", "rt") {|f|
        assert_equal("a\n", f.gets)
        assert_equal("b\n", f.gets)
        assert_equal("c\n", f.gets)
        assert_equal(nil, f.gets)
      }
    }
  end

  def test_textmode_decode_universal_newline_utf16
    with_tmpdir {
      generate_file("t.utf16be.crlf", "\0a\0\r\0\n\0b\0\r\0\n\0c\0\r\0\n")
      assert_equal("a\nb\nc\n", File.read("t.utf16be.crlf", mode:"rt:utf-16be:utf-8"))

      generate_file("t.utf16le.crlf", "a\0\r\0\n\0b\0\r\0\n\0c\0\r\0\n\0")
      assert_equal("a\nb\nc\n", File.read("t.utf16le.crlf", mode:"rt:utf-16le:utf-8"))

      generate_file("t.utf16be.cr", "\0a\0\r\0b\0\r\0c\0\r")
      assert_equal("a\nb\nc\n", File.read("t.utf16be.cr", mode:"rt:utf-16be:utf-8"))

      generate_file("t.utf16le.cr", "a\0\r\0b\0\r\0c\0\r\0")
      assert_equal("a\nb\nc\n", File.read("t.utf16le.cr", mode:"rt:utf-16le:utf-8"))

      generate_file("t.utf16be.lf", "\0a\0\n\0b\0\n\0c\0\n")
      assert_equal("a\nb\nc\n", File.read("t.utf16be.lf", mode:"rt:utf-16be:utf-8"))

      generate_file("t.utf16le.lf", "a\0\n\0b\0\n\0c\0\n\0")
      assert_equal("a\nb\nc\n", File.read("t.utf16le.lf", mode:"rt:utf-16le:utf-8"))
    }
  end

  SYSTEM_NEWLINE = []
  def system_newline
    return SYSTEM_NEWLINE.first if !SYSTEM_NEWLINE.empty?
    with_tmpdir {
      open("newline", "wt") {|f|
        f.print "\n"
      }
      open("newline", "rb") {|f|
        SYSTEM_NEWLINE << f.read
      }
    }
    SYSTEM_NEWLINE.first
  end

  def test_textmode_encode_newline
    with_tmpdir {
      open("t.txt", "wt") {|f|
        f.puts "abc"
        f.puts "def"
      }
      content = File.read("t.txt", :mode=>"rb")
      nl = system_newline
      assert_equal("abc#{nl}def#{nl}", content)
    }
  end

  def test_textmode_encode_newline_enc
    with_tmpdir {
      open("t.txt", "wt:euc-jp") {|f|
        f.puts "abc\u3042"
        f.puts "def\u3044"
      }
      content = File.read("t.txt", :mode=>"rb:ascii-8bit")
      nl = system_newline
      assert_equal("abc\xA4\xA2#{nl}def\xA4\xA4#{nl}", content)
    }
  end

  def test_textmode_read_ascii_incompat_internal
    with_tmpdir {
      generate_file("t.utf8.crlf", "a\r\nb\r\n")
      open("t.utf8.crlf", "rt:utf-8:utf-16be") {|f|
        content = f.read
        # textmode doesn't affect for ascii incompatible internal encoding.
        assert_equal("\0a\0\r\0\n\0b\0\r\0\n".force_encoding("UTF-16BE"),
                     content)
      }
    }
  end

  def test_textmode_write_ascii_incompat_internal
    with_tmpdir {
      open("t.utf8.lf", "wt:utf-8:utf-16be") {|f|
        f.print "\0a\0\n\0b\0\n".force_encoding("UTF-16BE")
      }
      content = File.read("t.utf8.lf", :mode=>"rb:ascii-8bit")
      # textmode doesn't affect for ascii incompatible internal encoding.
      assert_equal("a\nb\n", content)
    }
  end

  def test_binary
    with_tmpdir {
      src = "a\nb\rc\r\nd\n"
      generate_file("t.txt", src)
      open("t.txt", "rb") {|f|
        assert_equal(src, f.read)
      }
      open("t.txt", "r", :binmode=>true) {|f|
        assert_equal(src, f.read)
      }
      if system_newline == "\n"
        open("t.txt", "r") {|f|
          assert_equal(src, f.read)
        }
      end
    }
  end

  def test_binmode
    with_tmpdir {
      src = "a\r\nb\r\nc\r\n"
      generate_file("t.txt", src)
      open("t.txt", "rt") {|f|
        assert_equal("a", f.getc)
        assert_equal("\n", f.getc)
        f.binmode
        assert_equal("\n", f.getc)
        assert_equal("b", f.getc)
        assert_equal("\r", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("c", f.getc)
        assert_equal("\r", f.getc)
        assert_equal("\n", f.getc)
        assert_equal(nil, f.getc)
      }
    }
  end

  def test_binmode2
    with_tmpdir {
      src = "a\r\nb\r\nc\r\n"
      generate_file("t.txt", src)
      open("t.txt", "rt:euc-jp:utf-8") {|f|
        assert_equal("a", f.getc)
        assert_equal("\n", f.getc)
        f.binmode
        assert_equal("\n", f.getc)
        assert_equal("b", f.getc)
        assert_equal("\r", f.getc)
        assert_equal("\n", f.getc)
        assert_equal("c", f.getc)
        assert_equal("\r", f.getc)
        assert_equal("\n", f.getc)
        assert_equal(nil, f.getc)
      }
    }
  end

  def test_invalid_r
    with_tmpdir {
      generate_file("t.txt", "a\x80b")
      open("t.txt", "r:utf-8:euc-jp", :invalid => :replace) {|f|
        assert_equal("a?b", f.read)
      }
      open("t.txt", "r:utf-8:euc-jp", :invalid => :ignore) {|f|
        assert_equal("ab", f.read)
      }
      open("t.txt", "r:utf-8:euc-jp", :undef => :replace) {|f|
        assert_raise(Encoding::InvalidByteSequence) { f.read }
        assert_equal("b", f.read)
      }
      open("t.txt", "r:utf-8:euc-jp", :undef => :ignore) {|f|
        assert_raise(Encoding::InvalidByteSequence) { f.read }
        assert_equal("b", f.read)
      }
    }
  end

  def test_undef_r
    with_tmpdir {
      generate_file("t.txt", "a\uFFFDb")
      open("t.txt", "r:utf-8:euc-jp", :undef => :replace) {|f|
        assert_equal("a?b", f.read)
      }
      open("t.txt", "r:utf-8:euc-jp", :undef => :ignore) {|f|
        assert_equal("ab", f.read)
      }
      open("t.txt", "r:utf-8:euc-jp", :invalid => :replace) {|f|
        assert_raise(Encoding::ConversionUndefined) { f.read }
        assert_equal("b", f.read)
      }
      open("t.txt", "r:utf-8:euc-jp", :invalid => :ignore) {|f|
        assert_raise(Encoding::ConversionUndefined) { f.read }
        assert_equal("b", f.read)
      }
    }
  end

  def test_invalid_w
    with_tmpdir {
      invalid_utf8 = "a\x80b".force_encoding("utf-8")
      open("t.txt", "w:euc-jp", :invalid => :replace) {|f|
        assert_nothing_raised { f.write invalid_utf8 }
      }
      assert_equal("a?b", File.read("t.txt"))

      open("t.txt", "w:euc-jp", :invalid => :ignore) {|f|
        assert_nothing_raised { f.write invalid_utf8 }
      }
      assert_equal("ab", File.read("t.txt"))

      open("t.txt", "w:euc-jp", :undef => :replace) {|f|
        assert_raise(Encoding::InvalidByteSequence) { f.write invalid_utf8 }
      }
      open("t.txt", "w:euc-jp", :undef => :ignore) {|f|
        assert_raise(Encoding::InvalidByteSequence) { f.write invalid_utf8 }
      }
    }
  end

  def test_undef_w_stateless
    with_tmpdir {
      generate_file("t.txt", "a\uFFFDb")
      open("t.txt", "w:euc-jp:utf-8", :undef => :replace) {|f|
        assert_nothing_raised { f.write "a\uFFFDb" }
      }
      assert_equal("a?b", File.read("t.txt"))
      open("t.txt", "w:euc-jp:utf-8", :undef => :ignore) {|f|
        assert_nothing_raised { f.write "a\uFFFDb" }
      }
      assert_equal("ab", File.read("t.txt"))
      open("t.txt", "w:euc-jp:utf-8", :invalid => :replace) {|f|
        assert_raise(Encoding::ConversionUndefined) { f.write "a\uFFFDb" }
      }
      open("t.txt", "w:euc-jp:utf-8", :invalid => :ignore) {|f|
        assert_raise(Encoding::ConversionUndefined) { f.write "a\uFFFDb" }
      }
    }
  end

  def test_undef_w_stateful
    with_tmpdir {
      generate_file("t.txt", "a\uFFFDb")
      open("t.txt", "w:iso-2022-jp:utf-8", :undef => :replace) {|f|
        assert_nothing_raised { f.write "a\uFFFDb" }
      }
      assert_equal("a?b", File.read("t.txt"))
      open("t.txt", "w:iso-2022-jp:utf-8", :undef => :ignore) {|f|
        assert_nothing_raised { f.write "a\uFFFDb" }
      }
      assert_equal("ab", File.read("t.txt"))
      open("t.txt", "w:iso-2022-jp:utf-8", :invalid => :replace) {|f|
        assert_raise(Encoding::ConversionUndefined) { f.write "a\uFFFDb" }
      }
      open("t.txt", "w:iso-2022-jp:utf-8", :invalid => :ignore) {|f|
        assert_raise(Encoding::ConversionUndefined) { f.write "a\uFFFDb" }
      }
    }
  end

end