Only attempt mock reset on instantiated singletons

Update ResetMocksTestExecutionListener to only attempt a mock reset when
a singleton has actually been created.

Fixes gh-5870

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

@@ -16,11 +16,14 @@
 
 package org.springframework.boot.test.mock.mockito;
 
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
 import org.mockito.Mockito;
 
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
-import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.test.context.TestContext;
@@ -56,11 +59,11 @@ public class ResetMocksTestExecutionListener extends AbstractTestExecutionListen
 			MockReset reset) {
 		ConfigurableListableBeanFactory beanFactory = applicationContext.getBeanFactory();
 		String[] names = beanFactory.getBeanDefinitionNames();
+		Set<String> instantiatedSingletons = new HashSet<String>(
+				Arrays.asList(beanFactory.getSingletonNames()));
 		for (String name : names) {
 			BeanDefinition definition = beanFactory.getBeanDefinition(name);
-			String scope = definition.getScope();
-			if (AbstractBeanDefinition.SCOPE_DEFAULT.equals(scope)
-					|| BeanDefinition.SCOPE_SINGLETON.equals(scope)) {
+			if (definition.isSingleton() && instantiatedSingletons.contains(name)) {
 				Object bean = beanFactory.getBean(name);
 				if (reset.equals(MockReset.get(bean))) {
 					Mockito.reset(bean);

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

@@ -26,6 +26,7 @@ import org.springframework.boot.test.mock.mockito.example.ExampleService;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.test.context.junit4.SpringRunner;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -80,6 +81,13 @@ public class ResetMocksTestExecutionListenerTests {
 			return mock(ExampleService.class);
 		}
 
+		@Bean
+		@Lazy
+		public ExampleService fail() {
+			// gh-5870
+			throw new RuntimeException();
+		}
+
 	}
 
 }