text: 
  import os
  from microbit import display, Image
  
  #We don't have space for Beowolf, so here's the next best thing...
  text = """
  ’Twas brillig, and the slithy toves
    Did gyre and gimble in the wabe:
  All mimsy were the borogoves,
    And the mome raths outgrabe.
  
  “Beware the Jabberwock, my son!
    The jaws that bite, the claws that catch!
  Beware the Jubjub bird, and shun
   The frumious Bandersnatch!”
  
  He took his vorpal sword in hand;
    Long time the manxome foe he sought—
  So rested he by the Tumtum tree
    And stood awhile in thought.
  
  And, as in uffish thought he stood,
    The Jabberwock, with eyes of flame,
  Came whiffling through the tulgey wood,
    And burbled as it came!
  
  One, two! One, two! And through and through
    The vorpal blade went snicker-snack!
  He left it dead, and with its head
    He went galumphing back.
  
  “And hast thou slain the Jabberwock?
    Come to my arms, my beamish boy!
  O frabjous day! Callooh! Callay!”
    He chortled in his joy.
  
  ’Twas brillig, and the slithy toves
    Did gyre and gimble in the wabe:
  All mimsy were the borogoves,
    And the mome raths outgrabe.
  """
  
  def test_read_while_writing():
      j1 = open("jabbawocky.txt", "w")
      j1.write(text)
      j2 = open("jabbawocky.txt")
      short = j2.read()
      assert text.startswith(short)
      del j2
      j1.close()
      j2 = open("jabbawocky.txt")
      assert j2.read() == text
      j2.close()
      os.remove("jabbawocky.txt")
  
  def test_removing_mid_read():
      with open("jabbawocky.txt", "w") as j:
          j.write(text)
      j = open("jabbawocky.txt")
      os.remove("jabbawocky.txt")
      try:
          j.read()
          assert False, "Shouldn't reach here"
      except OSError:
          pass
  
  def test_removing_mid_write():
      j = open("jabbawocky.txt", "w")
      os.remove("jabbawocky.txt")
      try:
          j.write(text)
          assert False, "Shouldn't reach here"
      except OSError:
          pass
  
  def test_repeated_write():
      for i in range(40):
          with open("jabbawocky.txt", "w") as j:
              j.write(text)
  
  display.clear()
  try:
      test_read_while_writing()
      test_removing_mid_read()
      test_removing_mid_write()
      test_repeated_write()
      print("File test: PASS")
      display.show(Image.HAPPY)
  except Exception as ae:
      display.show(Image.SAD)
      raise
  
  