Mock framework with Objectify?

Question

Is it possible to use some mocking framework with Objectify?

I've tried the following, but it doesn't work:

Foo mockFoo = mock(Foo.class);      
ObjectifyService.register(mockFoo.getClass());
ObjectifyUtil.get().put(mockFoo);

The error is:

java.lang.IllegalArgumentException: CGLIB$CALLBACK_0: org.mockito.internal.creation.MethodInterceptorFilter is not a supported property type.
    at com.google.appengine.api.datastore.DataTypeUtils.checkSupportedSingleValue(DataTypeUtils.java:184)
    at com.google.appengine.api.datastore.DataTypeUtils.checkSupportedValue(DataTypeUtils.java:157)
    at com.google.appengine.api.datastore.DataTypeUtils.checkSupportedValue(DataTypeUtils.java:123)
    at com.google.appengine.api.datastore.Entity.setProperty(Entity.java:320)
    at com.googlecode.objectify.impl.save.FieldSaver.setEntityProperty(FieldSaver.java:171)
    at com.googlecode.objectify.impl.save.LeafFieldSaver.saveValue(LeafFieldSaver.java:93)
    at com.googlecode.objectify.impl.save.FieldSaver.save(FieldSaver.java:156)
    at com.googlecode.objectify.impl.save.ClassSaver.save(ClassSaver.java:84)
    at com.googlecode.objectify.impl.Transmog.save(Transmog.java:342)
    at com.googlecode.objectify.impl.ConcreteEntityMetadata.toEntity(ConcreteEntityMetadata.java:231)
    at com.googlecode.objectify.impl.AsyncObjectifyImpl.put(AsyncObjectifyImpl.java:252)
    at com.googlecode.objectify.impl.AsyncObjectifyImpl.put(AsyncObjectifyImpl.java:229)
    at com.googlecode.objectify.impl.ObjectifyImpl.put(ObjectifyImpl.java:126)
    at org.foo.test.ApiTest.bar(ApiTest.java:89)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:49)
    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)

Am I doing something wrong, or is this just not possible?

Answer 1

In my opinion, mocking a framework as big as Objectify cannot rely upon Mockito.

public class ProductTest {
  @Rule
  public EmbeddedDataStore store = new EmbeddedDataStore();

  @Before
  public void register() {
    ObjectifyService.register(Product.class);
  }

  @Test
  public void accessObjectifyWithSuccess() {
    Objectify ofy = ObjectifyService.begin();
    ofy.put(new Product());
    assertEquals(1, ofy.query(Product.class).list().size());
  }
}

The @Rule loads the datastore before the test. Then, the Product class is registered and the integration tests are run.

So, with this technique, you can run tests on App Engine/Objectify without deploying an app.

The following code is one way to code the datastore rule:

import org.junit.rules.ExternalResource;
import com.google.appengine.tools.development.testing.LocalServiceTestHelper;

public class EmbeddedDataStore extends ExternalResource {
  private static LocalServiceTestHelper helper;

  @Override
  protected void before() throws Throwable {
    helper = new LocalServiceTestHelper(new LocalDatastoreServiceTestConfig(),
      new LocalBlobstoreServiceTestConfig(), new LocalTaskQueueTestConfig(),
      new LocalMemcacheServiceTestConfig());
  }

  @Override
  protected void after() {
    helper.tearDown();
  }
}