Migrate remaining JUnit 4 tests to JUnit Jupiter where feasible

In Spring Framework 5.2, we migrated most of the test suite from JUnit
4 to JUnit Jupiter; however, prior to this commit, several tests in the
spring-test module were still based on JUnit 4 unnecessarily.

Since we are now planning to deprecate our JUnit 4 support in 7.0, this
commit migrates our remaining JUnit 4 based tests to JUnit Jupiter
whenever feasible. In the process, test classes that previously resided
under the "junit4" package have been moved to new packages directly
under the "org.springframework.text.context" package, and several
classes have been renamed for greater clarity of purpose.

Consequently, the only remaining tests based on JUnit 4 are those tests
that are required to run with JUnit 4 in order to test our JUnit 4
support.

This commit also greatly simplifies exclusions for Checkstyle rules
pertaining to JUnit usage.

See gh-23451
See gh-34794
Closes gh-34813

Author: sbrannen

spring-test/src/test/java/org/springframework/test/context/junit4/spr6128/AutowiredQualifierTests.java renamed to spring-test/src/test/java/org/springframework/test/context/AutowiredQualifierTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -14,30 +14,26 @@
  * limitations under the License.
  */
 
-package org.springframework.test.context.junit4.spr6128;
+package org.springframework.test.context;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
- * Integration tests to verify claims made in <a
- * href="https://jira.springframework.org/browse/SPR-6128"
- * target="_blank">SPR-6128</a>.
+ * Integration tests to verify claims made in
+ * <a href="https://github.com/spring-projects/spring-framework/issues/10796">gh-10796</a>.
  *
  * @author Sam Brannen
  * @author Chris Beams
  * @since 3.0
  */
-@ContextConfiguration
-@RunWith(SpringJUnit4ClassRunner.class)
-public class AutowiredQualifierTests {
+@SpringJUnitConfig
+class AutowiredQualifierTests {
 
 	@Autowired
 	private String foo;
@@ -48,7 +44,7 @@ public class AutowiredQualifierTests {
 
 
 	@Test
-	public void test() {
+	void test() {
 		assertThat(foo).isEqualTo("normal");
 		assertThat(customFoo).isEqualTo("custom");
 	}

spring-test/src/test/java/org/springframework/test/context/ContextHierarchyDirtiesContextTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -20,9 +20,8 @@
 import org.junit.jupiter.api.MethodOrderer;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestMethodOrder;
-import org.junit.runner.JUnitCore;
-import org.junit.runner.Result;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.junit.platform.testkit.engine.EngineTestKit;
 
 import org.springframework.beans.BeansException;
 import org.springframework.context.ApplicationContext;
@@ -32,9 +31,10 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.annotation.DirtiesContext.HierarchyMode;
-import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClass;
 
 /**
  * Integration tests that verify proper behavior of {@link DirtiesContext @DirtiesContext}
@@ -87,9 +87,11 @@ void methodLevelDirtiesContextWithExhaustiveHierarchyMode() {
 	private void runTestAndVerifyHierarchies(Class<? extends FooTestCase> testClass, boolean isFooContextActive,
 			boolean isBarContextActive, boolean isBazContextActive) {
 
-		JUnitCore jUnitCore = new JUnitCore();
-		Result result = jUnitCore.run(testClass);
-		assertThat(result.wasSuccessful()).as("all tests passed").isTrue();
+		EngineTestKit.engine("junit-jupiter")
+				.selectors(selectClass(testClass))
+				.execute()
+				.testEvents()
+				.assertStatistics(stats -> stats.started(1).succeeded(1).failed(0));
 
 		assertThat(ContextHierarchyDirtiesContextTests.context).isNotNull();
 
@@ -111,7 +113,7 @@ private void runTestAndVerifyHierarchies(Class<? extends FooTestCase> testClass,
 
 	// -------------------------------------------------------------------------
 
-	@RunWith(SpringRunner.class)
+	@ExtendWith(SpringExtension.class)
 	@ContextHierarchy(@ContextConfiguration(name = "foo"))
 	abstract static class FooTestCase implements ApplicationContextAware {
 
@@ -170,10 +172,10 @@ String bean() {
 	 * context.
 	 */
 	@DirtiesContext
-	public static class ClassLevelDirtiesContextWithExhaustiveModeTestCase extends BazTestCase {
+	static class ClassLevelDirtiesContextWithExhaustiveModeTestCase extends BazTestCase {
 
-		@org.junit.Test
-		public void test() {
+		@Test
+		void test() {
 		}
 	}
 
@@ -184,10 +186,10 @@ public void test() {
 	 * beginning from the current context hierarchy and down through all subhierarchies.
 	 */
 	@DirtiesContext(hierarchyMode = HierarchyMode.CURRENT_LEVEL)
-	public static class ClassLevelDirtiesContextWithCurrentLevelModeTestCase extends BazTestCase {
+	static class ClassLevelDirtiesContextWithCurrentLevelModeTestCase extends BazTestCase {
 
-		@org.junit.Test
-		public void test() {
+		@Test
+		void test() {
 		}
 	}
 
@@ -199,11 +201,11 @@ public void test() {
 	 * parent context, and then back down through all subhierarchies of the parent
 	 * context.
 	 */
-	public static class MethodLevelDirtiesContextWithExhaustiveModeTestCase extends BazTestCase {
+	static class MethodLevelDirtiesContextWithExhaustiveModeTestCase extends BazTestCase {
 
-		@org.junit.Test
+		@Test
 		@DirtiesContext
-		public void test() {
+		void test() {
 		}
 	}
 
@@ -213,11 +215,11 @@ public void test() {
 	 * <p>After running this test class, the context cache should be cleared
 	 * beginning from the current context hierarchy and down through all subhierarchies.
 	 */
-	public static class MethodLevelDirtiesContextWithCurrentLevelModeTestCase extends BazTestCase {
+	static class MethodLevelDirtiesContextWithCurrentLevelModeTestCase extends BazTestCase {
 
-		@org.junit.Test
+		@Test
 		@DirtiesContext(hierarchyMode = HierarchyMode.CURRENT_LEVEL)
-		public void test() {
+		void test() {
 		}
 	}
 

spring-test/src/test/java/org/springframework/test/context/SpringTestContextFrameworkTestSuite.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -16,6 +16,8 @@
 
 package org.springframework.test.context;
 
+import org.junit.jupiter.api.ClassOrderer;
+import org.junit.platform.suite.api.ConfigurationParameter;
 import org.junit.platform.suite.api.ExcludeTags;
 import org.junit.platform.suite.api.IncludeClassNamePatterns;
 import org.junit.platform.suite.api.SelectPackages;
@@ -44,5 +46,9 @@
 @SelectPackages("org.springframework.test.context")
 @IncludeClassNamePatterns(".*Tests?$")
 @ExcludeTags("failing-test-case")
+@ConfigurationParameter(
+		key = ClassOrderer.DEFAULT_ORDER_PROPERTY_NAME,
+		value = "org.junit.jupiter.api.ClassOrderer$ClassName"
+	)
 class SpringTestContextFrameworkTestSuite {
 }

spring-test/src/test/java/org/springframework/test/context/annotation/AnnotationConfigTestSuite.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2002-2025 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.annotation;
+
+import org.junit.jupiter.api.ClassOrderer;
+import org.junit.platform.suite.api.ConfigurationParameter;
+import org.junit.platform.suite.api.IncludeClassNamePatterns;
+import org.junit.platform.suite.api.IncludeEngines;
+import org.junit.platform.suite.api.SelectPackages;
+import org.junit.platform.suite.api.Suite;
+
+/**
+ * JUnit Platform based test suite annotation-driven <em>configuration class</em>
+ * support in the Spring TestContext Framework.
+ *
+ * <p><strong>This suite is only intended to be used manually within an IDE.</strong>
+ *
+ * <h3>Logging Configuration</h3>
+ *
+ * <p>In order for our log4j2 configuration to be used in an IDE, you must
+ * set the following system property before running any tests &mdash; for
+ * example, in <em>Run Configurations</em> in Eclipse.
+ *
+ * <pre style="code">
+ * -Djava.util.logging.manager=org.apache.logging.log4j.jul.LogManager
+ * </pre>
+ *
+ * @author Sam Brannen
+ * @since 3.1
+ */
+@Suite
+@IncludeEngines("junit-jupiter")
+@SelectPackages("org.springframework.test.context.annotation")
+@IncludeClassNamePatterns(".*Tests$")
+@ConfigurationParameter(
+	key = ClassOrderer.DEFAULT_ORDER_PROPERTY_NAME,
+	value = "org.junit.jupiter.api.ClassOrderer$ClassName"
+)
+public class AnnotationConfigTestSuite {
+}

spring-test/src/test/java/org/springframework/test/context/junit4/annotation/BeanOverridingDefaultConfigClassesInheritedTests.java renamed to spring-test/src/test/java/org/springframework/test/context/annotation/BeanOverridingDefaultConfigClassesInheritedTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-package org.springframework.test.context.junit4.annotation;
+package org.springframework.test.context.annotation;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.testfixture.beans.Employee;
 import org.springframework.context.annotation.Bean;
@@ -36,13 +36,21 @@
  * @since 3.1
  */
 @ContextConfiguration
-public class BeanOverridingDefaultConfigClassesInheritedTests extends DefaultConfigClassesBaseTests {
+class BeanOverridingDefaultConfigClassesInheritedTests extends DefaultConfigClassesBaseTests {
 
-	@Configuration
+	@Test
+	@Override
+	void verifyEmployeeSetFromBaseContextConfig() {
+		assertThat(this.employee).as("The employee should have been autowired.").isNotNull();
+		assertThat(this.employee.getName()).as("The employee bean should have been overridden.").isEqualTo("Yoda");
+	}
+
+
+	@Configuration(proxyBeanMethods = false)
 	static class ContextConfiguration {
 
 		@Bean
-		public Employee employee() {
+		Employee employee() {
 			Employee employee = new Employee();
 			employee.setName("Yoda");
 			employee.setAge(900);
@@ -51,12 +59,4 @@ public Employee employee() {
 		}
 	}
 
-
-	@Test
-	@Override
-	public void verifyEmployeeSetFromBaseContextConfig() {
-		assertThat(this.employee).as("The employee should have been autowired.").isNotNull();
-		assertThat(this.employee.getName()).as("The employee bean should have been overridden.").isEqualTo("Yoda");
-	}
-
 }

spring-test/src/test/java/org/springframework/test/context/junit4/annotation/BeanOverridingExplicitConfigClassesInheritedTests.java renamed to spring-test/src/test/java/org/springframework/test/context/annotation/BeanOverridingExplicitConfigClassesInheritedTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-package org.springframework.test.context.junit4.annotation;
+package org.springframework.test.context.annotation;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.test.context.ContextConfiguration;
 
@@ -33,11 +33,11 @@
  * @since 3.1
  */
 @ContextConfiguration(classes = BeanOverridingDefaultConfigClassesInheritedTests.ContextConfiguration.class)
-public class BeanOverridingExplicitConfigClassesInheritedTests extends ExplicitConfigClassesBaseTests {
+class BeanOverridingExplicitConfigClassesInheritedTests extends ExplicitConfigClassesBaseTests {
 
 	@Test
 	@Override
-	public void verifyEmployeeSetFromBaseContextConfig() {
+	void verifyEmployeeSetFromBaseContextConfig() {
 		assertThat(this.employee).as("The employee should have been autowired.").isNotNull();
 		assertThat(this.employee.getName()).as("The employee bean should have been overridden.").isEqualTo("Yoda");
 	}