无法测试 class return customException

Question

在试验 JUnit 时，我正在尝试测试一个简单的私有方法，如下所示，该方法接收一个字符串并确保它不包含单词 'Dummy'。

我知道，可以将测试放在与 class 相同的包 中，并将方法的访问修饰符更改为包，但我想用反思来学习。

private void validateString(String myString) throws CustomException {

    if (myString.toLowerCase().matches(".*dummy.*"))
        throw new CustomException("String has the invalid word!");

}

我试图通过反射访问私有方法，但测试失败！它显示以下异常：

java.lang.AssertionError:Expected test to throw
(an instance of com.myproject.exception.CustomException and exception 
with message a string containing "String has the invalid word!")

根据这个 question 的回答，我也在抓取 InvocationTargetException。

JUnit

    @Rule
    public ExpectedException thrown = ExpectedException.none();

    @Test
    public void shouldThrowExceptionForInvalidString() {

        thrown.expect(CustomException.class);
        thrown.expectMessage("String has the invalid word!");

        try {
            MyClass myCls = new MyClass();
            Method valStr = myCls.getClass().getDeclaredMethod(
                    "validateString", String.class);
            valStr.setAccessible(true);
            valStr.invoke(myCls, "This is theDummyWord find it if you can.");
        } catch (InvocationTargetException | NoSuchMethodException
                | SecurityException | IllegalAccessException
                | IllegalArgumentException n) {
            if (n.getCause().getClass() == CustomException.class) {
                throw new CustomException("String has the invalid word!");
            }
        }

    }

Answer 1

我同意上面评论中@Stultuske 的观点，并将测试重写为：

@Test
public void shouldThrowExceptionForInvalidString() {

    try {
        MyClass myCls = new MyClass();
        Method valStr = myCls.getClass().getDeclaredMethod(
                "validateString", String.class);
        valStr.setAccessible(true);
        valStr.invoke(myCls, "This is theDummyWord find it if you can.");
    } catch (Exception e) {
        assert(e instanceOf CustomException);
        assert(e.getMessage.equals("String has the invalid word!"));
    }

}

或者如果你想使用 ExpectedException

@Rule
public ExpectedException thrown = ExpectedException.none();

@Test
public void shouldThrowExceptionForInvalidString() {

    thrown.expect(CustomException.class);
    thrown.expectMessage("String has the invalid word!");

    MyClass myCls = new MyClass();
    Method valStr = myCls.getClass().getDeclaredMethod("validateString", String.class);
    valStr.setAccessible(true);
    valStr.invoke(myCls, "This is theDummyWord find it if you can.");

}

无法测试 class return customException

Cannot test a class that return a customException

java

reflection

junit