[quarkusio#36582] Add test case to TransactionalUniAsserterTest

Test that `assert.fail()` actually makes the test fails

integration-tests/hibernate-reactive-panache/src/test/java/io/quarkus/it/panache/reactive/TransactionalUniAsserterTest.java

@@ -3,9 +3,12 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;
 
+import org.opentest4j.AssertionFailedError;
+
 import io.quarkus.hibernate.reactive.panache.Panache;
 import io.quarkus.test.hibernate.reactive.panache.TransactionalUniAsserter;
 import io.quarkus.test.junit.QuarkusTest;
@@ -30,4 +33,9 @@ public void testTransactionalUniAsserter(TransactionalUniAsserter asserter) {
         });
     }
 
+    @Test
+    @RunOnVertxContext
+    public void testFailure(final TransactionalUniAsserter asserter) {
+        assertThrows(AssertionFailedError.class, asserter::fail);
+    }
 }