def test_decrement_pointer(self):
"""
Test that executing a '<' command decrements the pointer
by the correct amount.
There is no need to test wrapping, as it is accomodated
by modify_pointer.
"""
program = Program(2)
program.modify_pointer(1)
program.execute_one("<")
self.assertEqual(program.pointer, 0,
"Pointer should be decremented by 1")
def test_modify_pointer(self):
"""
Test that modify pointer increments and decrements
the pointer by the correct amount, and wraps around
by the correct number of cells.
"""
program = Program(3)
program.modify_pointer(2)
self.assertEqual(program.pointer, 2,
"Pointer should be incremented by 2")
program.modify_pointer(-2)
self.assertEqual(program.pointer, 0,
"Pointer should be decremented by 2")
program.modify_pointer(3)
self.assertEqual(program.pointer, 0,
"Pointer should be incremented by 3 and wrap around")