mockito - Issues with testing Spring's declarative caching support on a Spring data repository

Question

I am trying to test Spring caching support (as described here) for a Spring Data JPA repository (that extends JpaRepository) and I am actually having issues with my configuration.

Here is my repository method:

@Cacheable(value = CacheConfiguration.DATABASE_CACHE_NAME)
Member findByEmail(String email);

Here is my CacheConfiguration:

@Configuration
@EnableCaching
public class CacheConfiguration implements CachingConfigurer {

    public static final String DATABASE_CACHE_NAME = "cache.database";

    @Bean
    @Override
    public CompositeCacheManager cacheManager() {
        CompositeCacheManager cacheManager = new CompositeCacheManager(simpleCacheManager());
        cacheManager.setFallbackToNoOpCache(Boolean.FALSE);
        return cacheManager;
    }

    @Bean
    public CacheManager simpleCacheManager() {
        SimpleCacheManager simpleCacheManager = new SimpleCacheManager();
        List<ConcurrentMapCache> cacheList = new ArrayList<>();
        cacheList.add(createConcurrentMapCache(60L, DATABASE_CACHE_NAME, 50L));
        simpleCacheManager.setCaches(cacheList);
        return simpleCacheManager;
    }


    private ConcurrentMapCache createConcurrentMapCache(Long timeToLive, String name, long cacheSize) {
        CacheBuilder<Object, Object> cacheBuilder = CacheBuilder.newBuilder().expireAfterWrite(timeToLive, TimeUnit.SECONDS);
        if (cacheSize >= 0) {
            cacheBuilder.maximumSize(cacheSize);
        }
        ConcurrentMap<Object, Object> map = cacheBuilder.build().asMap();
        return new ConcurrentMapCache(name, map, false);
    }

    @Override
    public KeyGenerator keyGenerator() {
        return new SimpleKeyGenerator();
    }

}

Here is my test:

@ActiveProfiles(Profiles.TEST)
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = { FullIntegrationTestConfiguration.class, BaseTestConfiguration.class, MemberCachingIntegrationTest.Config.class })
public class MemberCachingIntegrationTest {

    private static final Member MEMBER_ONE = new Member();
    private static final Member MEMBER_TWO = new Member();

    @Autowired
    private MemberRepository memberRepositoryMock;

    @Before
    public void setup() {
        when(memberRepositoryMock.findByEmail(eq("foo@foo.com"))).thenReturn(MEMBER_ONE);//NPE Here
        when(memberRepositoryMock.findByEmail(eq("bar@bar.com"))).thenReturn(MEMBER_TWO);
    }

    @Test
    public void testFindByEmail() {
        Member firstInvocation = memberRepositoryMock.findByEmail("foo@foo.com");
        assertThat(firstInvocation, is(MEMBER_ONE));

        Member secondInvocation = memberRepositoryMock.findByEmail("foo@foo.com");
        assertThat(secondInvocation, is(MEMBER_ONE));

        verify(memberRepositoryMock, times(1)).findByEmail("foo@foo.com");
    }

    @Profile(Profiles.TEST)
    @Configuration
    static class Config {

        @Bean
        public MemberRepository memberRepositoryMock() {
            return mock(MemberRepository.class);
        }
    }
}

By running the above test, I noticed that a object of type SimpleKey is passed as the key and a null as the value to ConcurrentMapCache:

@Override
public void put(Object key, Object value) {
    this.store.put(key, toStoreValue(value));
}

In my case the store is of type: com.google.common.cache.LocalCache and the put method has a null check resulting in a NPE....

Here is the stack trace:

java.lang.NullPointerException
    at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:191)
    at com.google.common.cache.LocalCache.put(LocalCache.java:4210)
    at org.springframework.cache.concurrent.ConcurrentMapCache.put(ConcurrentMapCache.java:121)
    at org.springframework.cache.interceptor.CacheAspectSupport$CachePutRequest.apply(CacheAspectSupport.java:459)
    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:226)
    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:181)
    at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:60)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
    at com.sun.proxy.$Proxy93.findByEmail(Unknown Source)
    at com.bignibouX.tests.repository.member.MemberCachingIntegrationTest.setup(MemberCachingIntegrationTest.java:43)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    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.RunBefores.evaluate(RunBefores.java:24)
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:233)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
    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.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:176)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Answer 1

Your memberRepositoryMock that you try to use in when() is already a bean with cache advice around.

do something like this (I don't especially like the static member, but seems less ugly than getting advised bean using spring internals):

// this is actuall mock
private static MemberRepository myMock = mock(MemberRepository.class);

// this is mock wrapped behind cache
@Autowired
private MemberRepository memberRepositoryMock;

@Before
public void setup() {
    // using real mock for mockito stuff
    reset(myMock); // needed for tests where spring config is cached (= mock is not recreated between tests)
    when(myMock.findByEmail(eq("foo@foo.com"))).thenReturn(MEMBER_ONE);//NPE Here
    when(myMock.findByEmail(eq("bar@bar.com"))).thenReturn(MEMBER_TWO);
}

@Test
public void testFindByEmail() {
    // using adviced bean in test
    Member firstInvocation = memberRepositoryMock.findByEmail("foo@foo.com");
    assertThat(firstInvocation, is(MEMBER_ONE));

    Member secondInvocation = memberRepositoryMock.findByEmail("foo@foo.com");
    assertThat(secondInvocation, is(MEMBER_ONE));

    // again real mock, not bean here
    verify(myMock, times(1)).findByEmail("foo@foo.com");
}

@Profile(Profiles.TEST)
@Configuration
static class Config {

    @Bean
    public MemberRepository memberRepositoryMock() {
        return myMock;
    }
}