require 'test_helper'

# File SysSeek test class
class FileSysSeek < Minitest::Test
  def setup
    FakeFS.activate!
    FakeFS::FileSystem.clear
  end

  def teardown
    FakeFS.deactivate!
  end

  def test_should_seek_to_position
    File.open('foo', 'w') do |f|
      f << '0123456789'
    end

    File.open('foo', 'r') do |f|
      f.sysseek(3)
      assert_equal 3, f.pos

      f.sysseek(0)
      assert_equal 0, f.pos
    end
  end

  def test_seek_returns_offset_into_file
    File.open('foo', 'w') do |f|
      # 66 chars long
      str = '0123456789' \
            '0123456789' \
            '0123456789' \
            '0123456789' \
            '0123456789' \
            '0123456789' \
            '012345'

      f << str
    end

    f = File.open('foo')
    assert_equal 53, f.sysseek(-13, IO::SEEK_END)
  end
end
