Unable to mock class in mockito - maven

Question

I am trying to write a unit test for a sonar plugin. However, on mocking its Project class, the test fails as Mockito tries to use a wrong classname.
my test code is:
import org.sonar.api.resources.Project;
Project project = mock(Project.class);
On running the unit test, either through maven or directly in eclipse, the following stacktrace comes up:
java.lang.NoClassDefFoundError: org/apache/maven/project/MavenProject
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
at java.lang.Class.getDeclaredMethods(Class.java:1791)
at org.mockito.cglib.core.ReflectUtils.addAllMethods(ReflectUtils.java:349)
at org.mockito.cglib.proxy.Enhancer.getMethods(Enhancer.java:422)
at org.mockito.cglib.proxy.Enhancer.generateClass(Enhancer.java:457)
at org.mockito.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
at org.mockito.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:217)
at org.mockito.cglib.proxy.Enhancer.createHelper(Enhancer.java:378)
at org.mockito.cglib.proxy.Enhancer.createClass(Enhancer.java:318)
at org.mockito.internal.creation.jmock.ClassImposterizer.createProxyClass(ClassImposterizer.java:93)
at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:50)
at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:54)
at org.mockito.internal.MockitoCore.mock(MockitoCore.java:45)
at org.mockito.Mockito.mock(Mockito.java:921)
at org.mockito.Mockito.mock(Mockito.java:816)
at com.databorough.sonar.xametric.MetricAnalysisSensorTest.shouldExecuteOnProjectWithAllParams(MetricAnalysisSensorTest.java:37)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
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.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
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$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:113)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: java.lang.ClassNotFoundException: org.apache.maven.project.MavenProject
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
... 47 more
The project is in the classpath as the plugin builds successfully.
How can I set the test runner/maven to treat Project as org.sonar.api.resources.Project class?

Answer 1

Your "Project" class is correctly treated as "org.sonar.api.resources.Project".
The problem comes from the fact that Sonar internally uses "org.apache.maven.project.MavenProject", so this class must be on your test classpath. Adding the following dependency to your POM will solve the issue:
<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-project</artifactId>
<version>2.0.6</version>
<scope>test</scope>
</dependency>

Answer 2

java.lang.NoClassDefFoundError: org/apache/maven/project/MavenProject
this suggests that class org.sonar.api.resources.Project maybe depending on Maven class, org.apache.maven.project.MavenProject
I am not sure whether Sonar adds this as a dependency? You need to add dependency for Maven Plugin API maybe.