Add @MockitoBeanSettings, use MockitoSession with strict stubs default

This commit changes the way the `MockitoTestExecutionListener` sets up
mockito, now using the `MockitoSession` feature. Additionally, stubbing
now defaults to a STRICT mode which can be overruled with a newly
introduced annotation: `@MockitoBeanSettings`.

Closes gh-33318

spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/MockitoBeanSettingsLenientIntegrationTests.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2002-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.bean.override.mockito;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.mockito.quality.Strictness;
+
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+
+/**
+ * Integration tests for explicitly-defined {@link MockitoBeanSettings} with
+ * lenient stubbing.
+ *
+ * @author Simon Baslé
+ * @since 6.2
+ */
+@SpringJUnitConfig(MockitoBeanForByNameLookupIntegrationTests.Config.class)
+@MockitoBeanSettings(Strictness.LENIENT)
+public class MockitoBeanSettingsLenientIntegrationTests {
+
+	@Test
+	public void unusedStubbingNotReported() {
+		var list = Mockito.mock(List.class);
+		Mockito.when(list.get(Mockito.anyInt())).thenReturn(new Object());
+	}
+
+}

spring-test/src/test/java/org/springframework/test/context/bean/override/mockito/MockitoBeanSettingsStrictIntegrationTests.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2002-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.bean.override.mockito;
+
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.Named;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.junit.platform.testkit.engine.EngineTestKit;
+import org.junit.platform.testkit.engine.Events;
+import org.mockito.Mockito;
+import org.mockito.exceptions.misusing.UnnecessaryStubbingException;
+import org.mockito.quality.Strictness;
+
+import org.springframework.test.context.bean.override.mockito.MockitoBeanForByNameLookupIntegrationTests.Config;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+
+import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClass;
+import static org.junit.platform.testkit.engine.EventConditions.event;
+import static org.junit.platform.testkit.engine.EventConditions.finishedWithFailure;
+import static org.junit.platform.testkit.engine.EventConditions.test;
+import static org.junit.platform.testkit.engine.TestExecutionResultConditions.instanceOf;
+import static org.junit.platform.testkit.engine.TestExecutionResultConditions.message;
+
+/**
+ * Integration tests ensuring unnecessary stubbings are reported in various
+ * cases where a strict style is chosen or assumed.
+ *
+ * @author Simon Baslé
+ * @since 6.2
+ */
+public final class MockitoBeanSettingsStrictIntegrationTests {
+
+	private static Stream<Named<Class<?>>> strictCases() {
+		return Stream.of(
+				Named.of("explicit strictness", ExplicitStrictness.class),
+				Named.of("implicit strictness with @MockitoBean on field", ImplicitStrictnessWithMockitoBean.class)
+		);
+	}
+
+	@ParameterizedTest
+	@MethodSource("strictCases")
+	public void unusedStubbingIsReported(Class<?> forCase) {
+		Events events = EngineTestKit.engine("junit-jupiter")
+				.selectors(selectClass(forCase))
+				.execute()
+				.testEvents()
+				.assertStatistics(stats -> stats.started(1).failed(1));
+
+		events.assertThatEvents().haveExactly(1,
+				event(test("unnecessaryStub"),
+						finishedWithFailure(
+								instanceOf(UnnecessaryStubbingException.class),
+								message(msg -> msg.contains("Unnecessary stubbings detected.")))));
+	}
+
+	abstract static class BaseCase {
+		@Test
+		void unnecessaryStub() {
+			var list = Mockito.mock(List.class);
+			Mockito.when(list.get(Mockito.anyInt())).thenReturn(new Object());
+		}
+	}
+
+	@SpringJUnitConfig(Config.class)
+	@MockitoBeanSettings(Strictness.STRICT_STUBS)
+	static class ExplicitStrictness extends BaseCase {
+	}
+
+	@SpringJUnitConfig(Config.class)
+	static class ImplicitStrictnessWithMockitoBean extends BaseCase {
+
+		@MockitoBean
+		@SuppressWarnings("unused")
+		DateTimeFormatter ignoredMock;
+	}
+
+}