Pytest -在for循环中引发异常

Question

当计算机计数100倍时，当电池从设备上耗尽时，我尝试在pytest中引发异常。类：

class Calculator:
def __init__(self, battery: int = 100, filename=None):
    self.battery = battery
    self.filename = filename
    self.check_battery()

def check_battery(self):
    if self.battery <= 0:
        raise NoBatteryError("The battery has run out")

def add(self, *args):
    self.check_battery()
    self.battery -= 1
    result_add = 0

    for number_to_add in args:
        result_add += number_to_add
    return result_add


class NoBatteryError(Exception):
    pass

派泰斯特：

def test_battery_by_calculate_100x_times(calc):
    # Given
    for iteration in range(1, 103):
        value = 2
        result = calc.add(value, value)
        expected_value = value + value
        try:
            result == expected_value
        except NoBatteryError:
            assert True

输出：

FAILED test_electronic_device_calculator.py::test_battery_by_calculate_100x_times - electronic_devices.calculator.NoBatteryError: The battery has run out
=========1 failed, 29 passed in 0.20s =======

简单的测试，如：

def test_check_battery_should_raise_no_battery_error(calc):
    calc.battery = 0
    with pytest.raises(NoBatteryError):
        calc.check_battery()

为我工作。我尝试用pytest.raises(NoBatteryError)在for循环中使用--但是我的函数也不能工作。

Answer 1

我不确定它是否应该是这样的，但有效：

def test_battery_by_calculate_100x_times(calc):
for iteration in range(0, 102):
    value = 2
    try:
        calc.add(value, value)
    except NoBatteryError:
        assert True