def test_nextLineWithNoLines(self):
"""
Verify that retrieving the next line from an empty history object
returns an empty string.
"""
h = History()
self.assertEqual(h.nextLine(), "")
def test_nextLineWithOneLine(self):
"""
Verify that when positioned at the beginning and containing only one
line, the history object's C{nextLine} method returns an empty string.
"""
s = "hello"
h = History([s])
while h.previousLine():
pass
self.assertEqual(h.nextLine(), "")
def test_resetPosition(self):
"""
Verify that the position in the history object can be set to the end
using the C{resetPosition} method.
"""
s = "hello"
h = History()
h.addLine(s)
h.previousLine()
h.resetPosition()
self.assertEqual(h.nextLine(), "")
def test_nextLineWithTwoLines(self):
"""
Verify that when a history object contains two lines and is positioned
at the beginning, C{nextLine} first returns the second line and then
returns an empty string.
"""
s1 = "hello"
s2 = "world"
h = History([s1, s2])
while h.previousLine():
pass
self.assertEqual(h.nextLine(), s2)
self.assertEqual(h.nextLine(), "")
