java - 从 JMock 的对象返回 ImmutableSet 导致 UndeclaredThrowableException

Question

这是我希望通过的单元测试:

import static org.junit.Assert.assertEquals;

import org.jmock.Expectations;
import org.jmock.Mockery;
import org.junit.Test;

import com.google.common.collect.ImmutableSet;

public class JMockTest {

    @Test
    public void test() {
        Mockery mockery = new Mockery();

        final Foo foo = mockery.mock(Foo.class);
        mockery.checking(new Expectations() {{
            oneOf(foo).bar(); will(returnValue(ImmutableSet.<Long>of()));
        }});

        ImmutableSet<Long> result = foo.bar();
        assertEquals(ImmutableSet.<Long>of(), result);
    }

    interface Foo {
        ImmutableSet<Long> bar();
    }

}

但是，它会抛出这个错误:

java.lang.reflect.UndeclaredThrowableException
    at $Proxy3.bar(Unknown Source)
    at JMockTest$1.<init>(JMockTest.java:17)
    at JMockTest.test(JMockTest.java:16)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)
Caused by: java.lang.IllegalAccessException: Class org.jmock.internal.ReturnDefaultValueAction can not access a member of class com.google.common.collect.ImmutableSet with modifiers ""
    at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:102)
    at java.lang.Class.newInstance(Class.java:436)
    at org.jmock.internal.ReturnDefaultValueAction.collectionOrMapInstanceFor(ReturnDefaultValueAction.java:87)
    at org.jmock.internal.ReturnDefaultValueAction.invoke(ReturnDefaultValueAction.java:77)
    at org.jmock.internal.InvocationToExpectationTranslator.invoke(InvocationToExpectationTranslator.java:20)
    at org.jmock.internal.FakeObjectMethods.invoke(FakeObjectMethods.java:38)
    at org.jmock.lib.JavaReflectionImposteriser$1.invoke(JavaReflectionImposteriser.java:33)
    ... 26 more

看起来 JMock 正在内部尝试实例化一个 ImmutableSet，即使我为它提供了一个。

参见 ReturnDefaultValueAction:

private Object collectionOrMapInstanceFor(Class<?> returnType) throws Throwable {
  return returnType.isInterface() ? instanceForCollectionType(returnType) : returnType.newInstance();
}

returnType.isInterface() 是 false b/c 它是一个 ImmutableSet，所以 JMock 调用 ImmutableSet.newInstance()，它失败了 b/c ImmutableSet 没有可访问的构造函数。

我假设除了我以外的人之前都模拟过返回 guava 不可变集合对象的接口(interface)，或者返回没有可见构造函数的类的接口(interface)。你如何在 JMock 中处理这个问题？

编辑:这是 JMock 2.6.0

EDIT2:这适用于 JMock 2.8.2!

Answer 1

正如您所描述的，这似乎是您的 JMock 2.6.0 版本的错误。升级到最新的，目前是 2.8.2。该问题将消失。