# encoding: UTF-8

require 'json/stream'
require 'test/unit'

class BufferTest < Test::Unit::TestCase
  def setup
    @buf = JSON::Stream::Buffer.new
  end

  def test_single_byte_chars
    assert_equal("", @buf << "")
    assert_equal("abc", @buf << "abc")
    assert_equal("\u0000abc", @buf << "\u0000abc")
  end

  # The é character can be a single codepoint \u00e9 or two codepoints
  # \u0065\u0301. The first is encoded in 2 bytes, the second in 3 bytes.
  # The json and yajl-ruby gems and CouchDB do not normalize unicode text
  # so neither will we. Although, a good way to normalize is by calling
  # ActiveSupport::Multibyte::Chars.new("é").normalize(:c).
  def test_combined_chars
    assert_equal("\u0065\u0301", @buf << "\u0065\u0301")
    assert_equal(3, (@buf << "\u0065\u0301").bytesize)
    assert_equal(2, (@buf << "\u0065\u0301").size)

    assert_equal("\u00e9", @buf << "\u00e9")
    assert_equal(2, (@buf << "\u00e9").bytesize)
    assert_equal(1, (@buf << "\u00e9").size)
  end

  def test_valid_two_byte_chars
    assert_equal("abcé", @buf << "abcé")
    assert_equal("a", @buf << "a\xC3")
    assert_equal("é", @buf << "\xA9")
    assert_equal("", @buf << "\xC3")
    assert_equal("é", @buf << "\xA9")
    assert_equal("é", @buf << "\xC3\xA9")
  end

  def test_valid_three_byte_chars
    assert_equal("abcé\u2603", @buf << "abcé\u2603")
    assert_equal("a", @buf << "a\xE2")
    assert_equal("", @buf << "\x98")
    assert_equal("\u2603", @buf << "\x83")
  end

  def test_valid_four_byte_chars
    assert_equal("abcé\u2603\u{10102}é", @buf << "abcé\u2603\u{10102}é")
    assert_equal("a", @buf << "a\xF0")
    assert_equal("", @buf << "\x90")
    assert_equal("", @buf << "\x84")
    assert_equal("\u{10102}", @buf << "\x82")
  end

  def test_invalid_two_byte_start_chars
    assert_raise(JSON::Stream::ParserError) { @buf << "\xC3\xC3" }
  end

  def test_invalid_three_byte_start_chars
    assert_raise(JSON::Stream::ParserError) { @buf << "\xE2\xE2" }
  end

  def test_invalid_four_byte_start_chars
    assert_raise(JSON::Stream::ParserError) { @buf << "\xF0\xF0" }
  end

  def test_two_byte_start_with_single_byte_continuation_char
    assert_raise(JSON::Stream::ParserError) { @buf << "\xC3\u0000" }
  end

  def test_three_byte_start_with_single_byte_continuation_char
    assert_raise(JSON::Stream::ParserError) { @buf << "\xE2\u0010" }
  end

  def test_four_byte_start_with_single_byte_continuation_char
    assert_raise(JSON::Stream::ParserError) { @buf << "\xF0a" }
  end

  def test_invalid_continuation_char
    assert_raise(JSON::Stream::ParserError) { @buf << "\xA9" }
  end

  def test_overlong_form
    assert_raise(JSON::Stream::ParserError) { @buf << "\xC0\x80" }
  end
end