text: from __future__ import unicode_literals
  
  import pytest
  
  from prompt_toolkit_dev.buffer import Buffer
  
  
  @pytest.fixture
  def _buffer():
      buff = Buffer()
      return buff
  
  
  def test_initial(_buffer):
      assert _buffer.text == ''
      assert _buffer.cursor_position == 0
  
  
  def test_insert_text(_buffer):
      _buffer.insert_text('some_text')
      assert _buffer.text == 'some_text'
      assert _buffer.cursor_position == len('some_text')
  
  
  def test_cursor_movement(_buffer):
      _buffer.insert_text('some_text')
      _buffer.cursor_left()
      _buffer.cursor_left()
      _buffer.cursor_left()
      _buffer.cursor_right()
      _buffer.insert_text('A')
  
      assert _buffer.text == 'some_teAxt'
      assert _buffer.cursor_position == len('some_teA')
  
  
  def test_backspace(_buffer):
      _buffer.insert_text('some_text')
      _buffer.cursor_left()
      _buffer.cursor_left()
      _buffer.delete_before_cursor()
  
      assert _buffer.text == 'some_txt'
      assert _buffer.cursor_position == len('some_t')
  
  
  def test_cursor_up(_buffer):
      # Cursor up to a line thats longer.
      _buffer.insert_text('long line1\nline2')
      _buffer.cursor_up()
  
      assert _buffer.document.cursor_position == 5
  
      # Going up when already at the top.
      _buffer.cursor_up()
      assert _buffer.document.cursor_position == 5
  
      # Going up to a line that's shorter.
      _buffer.reset()
      _buffer.insert_text('line1\nlong line2')
  
      _buffer.cursor_up()
      assert _buffer.document.cursor_position == 5
  
  
  def test_cursor_down(_buffer):
      _buffer.insert_text('line1\nline2')
      _buffer.cursor_position = 3
  
      # Normally going down
      _buffer.cursor_down()
      assert _buffer.document.cursor_position == len('line1\nlin')
  
      # Going down to a line that's shorter.
      _buffer.reset()
      _buffer.insert_text('long line1\na\nb')
      _buffer.cursor_position = 3
  
      _buffer.cursor_down()
      assert _buffer.document.cursor_position == len('long line1\na')
  
  
  def test_join_next_line(_buffer):
      _buffer.insert_text('line1\nline2\nline3')
      _buffer.cursor_up()
      _buffer.join_next_line()
  
      assert _buffer.text == 'line1\nline2 line3'
  
      # Test when there is no '\n' in the text
      _buffer.reset()
      _buffer.insert_text('line1')
      _buffer.cursor_position = 0
      _buffer.join_next_line()
  
      assert _buffer.text == 'line1'
  
  
  def test_newline(_buffer):
      _buffer.insert_text('hello world')
      _buffer.newline()
  
      assert _buffer.text == 'hello world\n'
  
  
  def test_swap_characters_before_cursor(_buffer):
      _buffer.insert_text('hello world')
      _buffer.cursor_left()
      _buffer.cursor_left()
      _buffer.swap_characters_before_cursor()
  
      assert _buffer.text == 'hello wrold'
  