mythril/tests/laser/state/mstate_test.py

import pytest
from mythril.laser.ethereum.state import MachineState
from mythril.laser.ethereum.evm_exceptions import StackUnderflowException

memory_extension_test_data = [
    (0, 0, 10),
    (0, 30, 10),
    (100, 22, 8)
]


@pytest.mark.parametrize("initial_size,start,extension_size", memory_extension_test_data)
def test_memory_extension(initial_size, start, extension_size):
    # Arrange
    machine_state = MachineState(0)
    machine_state.memory = [0] * initial_size

    # Act
    machine_state.mem_extend(start, extension_size)

    # Assert
    assert machine_state.memory_size == len(machine_state.memory)
    assert machine_state.memory_size == max(initial_size, start + extension_size)


stack_pop_too_many_test_data = [
    (0, 1),
    (0, 2),
    (5, 1),
    (5, 10)
]


@pytest.mark.parametrize("initial_size,overflow", stack_pop_too_many_test_data)
def test_stack_pop_too_many(initial_size, overflow):
    # Arrange
    machine_state = MachineState(0)
    machine_state.stack = [42] * initial_size

    # Act + Assert
    with pytest.raises(StackUnderflowException):
        machine_state.pop(initial_size + overflow)


stack_pop_test_data = [
    ([1, 2, 3], 2, [3, 2]),
    ([1, 3, 4, 7, 7, 1, 2], 5, [2, 1, 7, 7, 4])
]


@pytest.mark.parametrize("initial_stack,amount,expected", stack_pop_test_data)
def test_stack_multiple_pop(initial_stack, amount, expected):
    # Arrange
    machine_state = MachineState(0)
    machine_state.stack = initial_stack[:]

    # Act
    results = machine_state.pop(amount)

    # Assert
    assert results == initial_stack[-amount:][::-1]
    assert results == expected
    assert len(machine_state.stack) == len(initial_stack) - amount


def test_stack_multiple_pop_():
    # Arrange
    machine_state = MachineState(0)
    machine_state.stack = [1, 2, 3]

    # Act
    a, b = machine_state.pop(2)

    # Assert
    assert a == 3
    assert b == 2


def test_stack_single_pop():
    # Arrange
    machine_state = MachineState(0)
    machine_state.stack = [1,2,3]

    # Act
    result = machine_state.pop()

    # Assert
    assert isinstance(result, int)


memory_write_test_data = [
    (5, 10, [1, 2, 3]),
    (0, 0, [3, 4]),
    (20, 1, [2, 4, 10])
]


@pytest.mark.parametrize("initial_size, memory_offset, data", memory_write_test_data)
def test_memory_write(initial_size, memory_offset, data):
    # Arrange
    machine_state = MachineState(0)
    machine_state.memory = [0]*initial_size

    # Act
    machine_state.memory_write(memory_offset, data)

    # Assert
    assert len(machine_state.memory) == max(initial_size, memory_offset+len(data))
    assert machine_state.memory[memory_offset:memory_offset+len(data)] == data