text: """Unit test for the 'fullmoon' helper"""
  
  import arrow
  import pytest
  
  from watson.fullmoon import get_last_full_moon
  
  
  def test_with_known_date():
      aniceday = arrow.Arrow(2018, 7, 27, 10, 51)
      aniceday_lastMoon = arrow.Arrow(2018, 6, 28, 4, 55)
      aniceday_result = get_last_full_moon(aniceday)
      assert aniceday_result == aniceday_lastMoon
      thenextday = aniceday.shift(days=1)
      thenextday_lastMoon = arrow.Arrow(2018, 7, 27, 20, 22)
      thenextday_result = get_last_full_moon(thenextday)
      assert thenextday_result == thenextday_lastMoon
  
  
  def test_invalid_ranges():
      fail = arrow.Arrow(1970, 1, 1)
      fail2 = arrow.Arrow(2100, 5, 5)
      with pytest.raises(ValueError):
          get_last_full_moon(fail)
      with pytest.raises(ValueError):
          get_last_full_moon(fail2)
  