Upgrade to JUnit 6.0.1 and prevent AOT scanning failure for JUnit 4 tests

This commit upgrades our test suite to use JUnit 6.0.1 and removes the
systemProperty("junit.platform.discovery.issue.severity.critical", "WARNING")
configuration from spring-test.gradle, so that all discovery issues will
fail the build for the spring-test module as well.

In addition, this commit prevents potential AOT test scanning failures
for JUnit 4 tests by setting the
"junit.vintage.discovery.issue.reporting.enabled" configuration
parameter to "false" in TestClassScanner.

See junit-team/junit-framework#5030
Closes gh-35740

Author: sbrannen

build.gradle

@@ -75,7 +75,7 @@ configure([rootProject] + javaProjects) { project ->
 			"https://hc.apache.org/httpcomponents-client-5.5.x/current/httpclient5/apidocs/",
 			"https://projectreactor.io/docs/test/release/api/",
 			"https://junit.org/junit4/javadoc/4.13.2/",
-			"https://docs.junit.org/6.0.0/api/",
+			"https://docs.junit.org/6.0.1/api/",
 			"https://www.reactive-streams.org/reactive-streams-1.0.3-javadoc/",
 			"https://r2dbc.io/spec/1.0.0.RELEASE/api/",
 			"https://jspecify.dev/docs/api/"

framework-platform/framework-platform.gradle

@@ -19,7 +19,7 @@ dependencies {
 	api(platform("org.eclipse.jetty.ee11:jetty-ee11-bom:12.1.3"))
 	api(platform("org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.10.2"))
 	api(platform("org.jetbrains.kotlinx:kotlinx-serialization-bom:1.9.0"))
-	api(platform("org.junit:junit-bom:6.0.0"))
+	api(platform("org.junit:junit-bom:6.0.1"))
 	api(platform("org.mockito:mockito-bom:5.20.0"))
 	api(platform("tools.jackson:jackson-bom:3.0.1"))
 

spring-test/spring-test.gradle

@@ -110,9 +110,10 @@ test {
 	// `include` test filters and system properties are configured in
 	// org.springframework.build.TestConventions in buildSrc.
 	filter.excludeTestsMatching("*TestCase")
-	// Override critical severity defined in TestConventions, since spring-test
-	// relies on the Vintage test engine for JUnit 4 support.
-	systemProperty("junit.platform.discovery.issue.severity.critical", "WARNING")
+	// Since spring-test relies on the Vintage test engine for JUnit 4 support,
+	// we disable reporting of the "deprecated" discovery issue, because that
+	// would otherwise fail the build.
+	systemProperty("junit.vintage.discovery.issue.reporting.enabled", "false")
 	// Optionally configure Java Util Logging for the JUnit Platform.
 	// systemProperty("java.util.logging.manager", "org.apache.logging.log4j.jul.LogManager")
 }

spring-test/src/main/java/org/springframework/test/context/aot/TestClassScanner.java

@@ -142,7 +142,12 @@ Stream<Class<?>> scan(String... packageNames) {
 		if (packageNames.length > 0) {
 			builder.filters(includePackageNames(packageNames));
 		}
-		LauncherDiscoveryRequest request = builder.build();
+		LauncherDiscoveryRequest request = builder
+				// In case junit.platform.discovery.issue.severity.critical=INFO has been configured,
+				// we do not want scanning to fail due to the deprecation of the Vintage test engine.
+				// So, we disable reporting of the deprecation discovery issue.
+				.configurationParameter("junit.vintage.discovery.issue.reporting.enabled", "false")
+				.build();
 		Launcher launcher = LauncherFactory.create();
 		TestPlan testPlan = launcher.discover(request);
 

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

@@ -46,9 +46,14 @@
 @SelectPackages("org.springframework.test.context")
 @IncludeClassNamePatterns(".*Tests?$")
 @ExcludeTags("failing-test-case")
+@ConfigurationParameter(
+		key = "junit.platform.discovery.issue.severity.critical",
+		value = "INFO")
+@ConfigurationParameter(
+		key = "junit.vintage.discovery.issue.reporting.enabled",
+		value = "false")
 @ConfigurationParameter(
 		key = ClassOrderer.DEFAULT_ORDER_PROPERTY_NAME,
-		value = "org.junit.jupiter.api.ClassOrderer$ClassName"
-	)
+		value = "org.junit.jupiter.api.ClassOrderer$ClassName")
 class SpringTestContextFrameworkTestSuite {
 }