java - mockito 使用 spy 进行更好的预期异常测试

Question

如何进行第 3 次测试以检查异常消息中是否存在 cause1？我还列出了前两个测试中有缺点的地方。首先是不检查消息，其次需要大量样板代码。

public class CheckExceptionsWithMockitoTest {

    @Test(expected = RuntimeException.class)
    public void testExpectedException1() {
        A a = new A();
        a.doSomethingThatThrows();
    }

    @Test
    public void testExpectedException2() {
        A a = new A();
        try {
            a.doSomethingThatThrows();
            fail("no exception thrown");
        } catch (RuntimeException e) {
            assertThat(e.getMessage(), org.hamcrest.Matchers.containsString("cause1"));
        }
    }

    @Test
    public void testExpectedException3() {
        A a = new A();
        A spyA = org.mockito.Mockito.spy(a);
        // valid but doesnt work
        // doThrow(new IllegalArgumentException()).when(spyA).doSomethingThatThrows();
        // invalid but in the spirit of what i want 
        //chekThrow(RuntimeException.class,containsString("cause1")).when(spyA).doSomethingThatThrows();
    }

}

我在 Mockito 中找不到有用的东西，但有些东西看起来可能(在语法级别)和功能。

---

使用 catchexception 我创建了这样的测试

import static com.googlecode.catchexception.CatchException.*;
import static com.googlecode.catchexception.apis.CatchExceptionHamcrestMatchers.*;
import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;

import org.junit.*;
public class CheckExceptionsWithMockitoTest{  
    //...
    @Test
    public void testExpectedException3() {
        A a = new A();
        verifyException(a,IllegalArgumentException.class)
            .doSomethingThatThrows();
        //if more details to be analized are needed
        assertThat(
            (IllegalStateException) caughtException(),
            allOf(
                is(IllegalStateException.class),
                hasMessageThat(
                        containsString("is not allowed to add counterparties")), 
                hasNoCause()));
        //more asserts could come
        assertNotNull(a);
    }
}

Answer 1

使用catch-exception库，或者我猜您正在寻找的解决方案是您的第二个实现。

@expected 没有提供任何方法来断言抛出的异常，除了它的类，所以你不能避免 try/catching(没有那么多样板代码!)

Mockito 不提供类似verifyThrows 方法的东西。

因此您可以用 try/catching 换取额外的库:使用 catch-exception ，您将能够在一行中捕获异常，并为进一步的断言做好准备。

示例源代码

A a = new A();

when(a).doSomethingThatThrows();

then(caughtException())
        .isInstanceOf(IllegalStateException.class)
        .hasMessageContaining("is not allowed to add counterparties")
        .hasNoCause();

依赖

'com.googlecode.catch-exception:catch-exception:1.2.0'