模拟对象不起作用

Question

double checkAndReturnDoubleIfOk(String stringToCheck) {
        double price = 0;
        try {
            price = Double.valueOf(stringToCheck);
        } catch (NumberFormatException e) {
            System.err.println("Price is not a number");
            return -1;
        }
        String[] array = stringToCheck.split("\\.");
        if (array[1].length() < 3 & price > 0) {
            return price;
        } else {
            throw new WrongCostFormat();
        }

    }

@Test(expected = WrongCostFormat.class)
    public void shouldThrowNumberFormatException() {

        Product mock = mock(Product.class);
        double number = mock.checkAndReturnDoubleIfOk("1.234");     

    }

我是JUnit和Mockito世界的新手,无法弄清楚,为什么测试失败了.有什么建议？我调试了测试文件,似乎数字是0.0而不是抛出异常...包异常;

public class WrongCostFormat extends RuntimeException {

    public WrongCostFormat() {
        super();
    }

    public WrongCostFormat(String s) {
        super(s);
    }

    public WrongCostFormat(String s, Throwable throwable) {
        super(s, throwable);
    }

    public WrongCostFormat(Throwable throwable) {
        super(throwable);
    }

}

Answer 1

如果你想测试checkAndReturnDoubleIfOk你不应该嘲笑它.

你所做的是错的 - 你是想模仿合作者,而不是被测试的课程.首先,您创建一个模拟,Product其中所有方法都被模拟(checkAndReturnDoubleIfOk也),然后尝试将其用作原始类.实际上你正在测试模拟的实现checkAndReturnDoubleIfOk.

你的代码应该是这样的:

@Test(expected = WrongCostFormat.class)
public void shouldThrowNumberFormatException() {
    Product p = new Product();
    p.checkAndReturnDoubleIfOk("1.234");     
}

当被测试的类使用另一个类时,应该被模拟的是另一个类.然后,您应该验证正在测试的类是否已与模拟类正确交互.