def test_data_past_ram_end_raises_indexerror(self, ram_size, location):
vm = VM(memory_size=ram_size)
# 1 after end of RAM
data_len = 1 + ram_size - location
with pytest.raises(IndexError):
vm.load_to_memory(b"a" * data_len, location)
def load_rom_to_vm(path: PathOrStr,
vm: VM = None,
location: int = 0x200) -> VM:
"""
Utility function to load a rom to a VM's memory space.
If the VM isn't provided, one is created.
Raises an error if it's too big for the allotted VM.
"""
path = clean_path(path)
vm = vm or VM()
with open(path, "rb") as rom_file:
rom_data = rom_file.read()
rom_size = len(rom_data)
mem_size = len(vm.memory)
if rom_size > mem_size - vm.program_counter:
raise IndexError(f"Rom file too big!"
f"{rom_size} > {mem_size - vm.program_counter}")
vm.load_to_memory(rom_data, location)
return vm
def test_bad_type_on_data_causes_typerror(self):
vm = VM()
with pytest.raises(TypeError):
vm.load_to_memory("bad", 0x200)
def test_good_values_sets_data(self, data):
vm = VM()
vm.load_to_memory(data, 0x200)
assert vm.memory[0x200:0x204] == data
def test_negative_location_causes_indexerror(self):
vm = VM()
with pytest.raises(IndexError):
vm.load_to_memory(b"aaa", -5)