Improve assertion failure message in TestClassPredicatesTests

The recursiveHierarchies() test currently fails when running in Eclipse IDE, but the failure message does not indicate what the expected message is for the expected JUnitException. This commit therefore updates the assertion to check the exception message to help with diagnostics. (cherry picked from commit 3c5b457)

Author: sbrannen

jupiter-tests/src/test/java/org/junit/jupiter/engine/discovery/predicates/TestClassPredicatesTests.java

@@ -11,8 +11,8 @@
 package org.junit.jupiter.engine.discovery.predicates;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.ArrayList;
@@ -218,7 +218,11 @@ void privateStaticTestClassEvaluatesToFalse() {
  */
 @Test
 void recursiveHierarchies() {
-assertThrows(JUnitException.class, () -> predicates.looksLikeIntendedTestClass(TestCases.OuterClass.class));
+assertThatExceptionOfType(JUnitException.class)//
+.isThrownBy(() -> predicates.looksLikeIntendedTestClass(TestCases.OuterClass.class))//
+.withMessage("Detected cycle in inner class hierarchy between %s and %s",
+TestCases.OuterClass.RecursiveInnerClass.class.getName(), TestCases.OuterClass.class.getName());
+
 assertTrue(predicates.isValidStandaloneTestClass(TestCases.OuterClass.class));
 assertThat(discoveryIssues).isEmpty();
 
@@ -404,6 +408,7 @@ void test() {
 @SuppressWarnings("InnerClassMayBeStatic")
 class RecursiveInnerClass extends OuterClass {
 }
+
 }
 
 private static class NestedClassesTestCase {