def test_increment_cell(self):
"""
Test that executing a '+' operation increments the cell
at the pointer by the correct amount.
"""
program = Program(1)
program.execute_one("+")
self.assertEqual(program.cell, 1, "Cell should be incremented to 1")
def test_decrement_cell(self):
"""
Test that executing a '-' operation decrements the cell
at the pointer by the correct amount.
"""
program = Program(1)
program.cell = 1
program.execute_one("-")
self.assertEqual(program.cell, 0, "Cell should be decremented to 0")
def test_loop(self):
"""
Test that a simple loop will repeat until the end condition
is met. The cell at the pointer should have a non-zero value
before the loop and be zero when after the loop.
"""
program = Program(1)
program.cell = 3
program.execute_one(["-"])
self.assertEqual(program.pointer, 0, "Pointer should be reduced to 0")
def test_increment_pointer(self):
"""
Test that executing a '>' command increments the pointer
by the correct amount.
There is no need to test wrapping, as it is accomodated
by modify_pointer.
"""
program = Program(2)
program.execute_one(">")
self.assertEqual(program.pointer, 1,
"Pointer should be incremented by 1")
def test_loop_complex(self):
"""
Test a complex program which uses a loop to multiply the contents
of its first cell into its second cell, by reducing the
first cell to zero in order to end the loop.
"""
program = Program(2)
program.execute_many(["+", "+", ["-", ">", "+", "+", "<"], ">"])
if program.pointer == 1 and program.cell == 4:
self.assertEqual(program.cells[0], 0, "Cell 0 should be 0")
else:
self.fail("Should be at cell 1 with value 4")
def test_init_pointer(self):
"""
Test that the program's pointer is initialised at 0.
"""
program = Program(3)
self.assertEqual(program.pointer, 0, "Pointer should equal 0")
def test_init_cells(self):
"""
Test that the program has the right number of cells,
with all initialised to zero.
"""
program = Program(4)
self.assertEqual(program.cells, [0, 0, 0, 0],
"Program should have 4 cells initialised to 0")
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")