Remove usage of Mockito's internals

Previously, we relied on Mockito's internals to bypass any Spring AOP
proxy during verification of a spy. Thanks to a new API in Mockito,
we can replace the use of Mockito's internals with a
VerificationStartedListener. This listener changes Mockito's view of
the mock to be the ultimate target of the AOP proxy, i.e. to be the
actual Mockito-created spy, allowing Mockito's verification of the
spy to proceed successfully.

This above-described change will mean that we require a very
up-to-date version of Mockito so the tests that verify our
compatibility with 2.5 have been removed as we will no longer support
it when using @MockBean or @SpyBean.

Lastly, two tests have been updated to replace their usage of the
internal MockUtil class with the equivalent public API calls.

Closes gh-10352

Author: wilkinsona

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockitoAopProxyTargetInterceptor.java

@@ -27,7 +27,6 @@
 import java.util.TreeSet;
 
 import org.springframework.aop.scope.ScopedProxyUtils;
-import org.springframework.aop.support.AopUtils;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.PropertyValues;
 import org.springframework.beans.factory.BeanClassLoaderAware;
@@ -391,25 +390,13 @@ private void inject(Field field, Object target, String beanName,
 			Assert.state(ReflectionUtils.getField(field, target) == null,
 					() -> "The field " + field + " cannot have an existing value");
 			Object bean = this.beanFactory.getBean(beanName, field.getType());
-			if (definition.isProxyTargetAware() && isAopProxy(bean)) {
-				MockitoAopProxyTargetInterceptor.applyTo(bean);
-			}
 			ReflectionUtils.setField(field, target, bean);
 		}
 		catch (Throwable ex) {
 			throw new BeanCreationException("Could not inject field: " + field, ex);
 		}
 	}
 
-	private boolean isAopProxy(Object object) {
-		try {
-			return AopUtils.isAopProxy(object);
-		}
-		catch (Throwable ex) {
-			return false;
-		}
-	}
-
 	@Override
 	public int getOrder() {
 		return Ordered.LOWEST_PRECEDENCE - 10;

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/MockitoPostProcessor.java

@@ -18,9 +18,12 @@
 
 import org.mockito.MockSettings;
 import org.mockito.Mockito;
+import org.mockito.listeners.VerificationStartedEvent;
+import org.mockito.listeners.VerificationStartedListener;
 
 import org.springframework.core.ResolvableType;
 import org.springframework.core.style.ToStringCreator;
+import org.springframework.test.util.AopTestUtils;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
@@ -93,7 +96,25 @@ public <T> T createSpy(String name, Object instance) {
 		}
 		settings.spiedInstance(instance);
 		settings.defaultAnswer(Mockito.CALLS_REAL_METHODS);
+		if (this.isProxyTargetAware()) {
+			settings.verificationStartedListeners(
+					new SpringAopBypassingVerificationStartedListener());
+		}
 		return (T) Mockito.mock(instance.getClass(), settings);
 	}
 
+	/**
+	 * A {@link VerificationStartedListener} that bypasses any proxy created by Spring AOP
+	 * when the verification of a spy starts.
+	 */
+	private static final class SpringAopBypassingVerificationStartedListener
+			implements VerificationStartedListener {
+
+		@Override
+		public void onVerificationStarted(VerificationStartedEvent event) {
+			event.setMock(AopTestUtils.getUltimateTargetObject(event.getMock()));
+		}
+
+	}
+
 }

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/mock/mockito/SpyDefinition.java

@@ -18,7 +18,7 @@
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.mockito.internal.util.MockUtil;
+import org.mockito.Mockito;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.mock.mockito.example.ExampleGenericStringServiceCaller;
@@ -50,7 +50,8 @@ public class SpyBeanOnTestFieldForMultipleExistingBeansWithOnePrimaryIntegration
 	@Test
 	public void testSpying() throws Exception {
 		assertThat(this.caller.sayGreeting()).isEqualTo("I say two");
-		assertThat(MockUtil.getMockName(this.spy).toString()).isEqualTo("two");
+		assertThat(Mockito.mockingDetails(this.spy).getMockCreationSettings()
+				.getMockName().toString()).isEqualTo("two");
 		verify(this.spy).greeting();
 	}
 

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/mock/mockito/Mockito25Tests.java

@@ -18,7 +18,8 @@
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.mockito.internal.util.MockUtil;
+import org.mockito.MockingDetails;
+import org.mockito.Mockito;
 
 import org.springframework.boot.test.mock.mockito.example.SimpleExampleStringGenericService;
 import org.springframework.context.annotation.Bean;
@@ -42,8 +43,10 @@ public class SpyBeanWithNameOnTestFieldForMultipleExistingBeansTests {
 
 	@Test
 	public void testSpying() throws Exception {
-		assertThat(MockUtil.isSpy(this.spy)).isTrue();
-		assertThat(MockUtil.getMockName(this.spy).toString()).isEqualTo("two");
+		MockingDetails mockingDetails = Mockito.mockingDetails(this.spy);
+		assertThat(mockingDetails.isMock()).isTrue();
+		assertThat(mockingDetails.getMockCreationSettings().getMockName().toString())
+				.isEqualTo("two");
 	}
 
 	@Configuration