Account for the null root bean when performing value validation

when Validator#validateValue is used then the root validation context won't have the root bean (i.e. it'll be null), but at the same time we've already retrieved the value since we passed it to the validator call, hence no need to check for reachability

Author: marko-bekhta

extensions/hibernate-orm/deployment/src/test/java/io/quarkus/hibernate/orm/validation/JPATestValidationOfNonEntitiesResource.java

@@ -0,0 +1,50 @@
+package io.quarkus.hibernate.orm.validation;
+
+import java.util.Set;
+
+import jakarta.enterprise.context.ApplicationScoped;
+import jakarta.inject.Inject;
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.Validator;
+import jakarta.validation.constraints.NotNull;
+import jakarta.ws.rs.GET;
+import jakarta.ws.rs.Path;
+
+@Path("/validation/nonentity")
+@ApplicationScoped
+public class JPATestValidationOfNonEntitiesResource {
+
+    @Inject
+    Validator validator;
+
+    @Path("/bean")
+    @GET
+    public String bean() {
+        Set<ConstraintViolation<MyNonEntity>> constraintViolations = validator.validate(new MyNonEntity());
+        if (constraintViolations.size() != 1) {
+            return "ko";
+        }
+        if (!constraintViolations.iterator().next().getPropertyPath().toString().equals("name")) {
+            return "ko";
+        }
+        return "ok";
+    }
+
+    @Path("/value")
+    @GET
+    public String value() {
+        Set<ConstraintViolation<MyNonEntity>> constraintViolations = validator.validateValue(MyNonEntity.class, "name", null);
+        if (constraintViolations.size() != 1) {
+            return "ko";
+        }
+        if (!constraintViolations.iterator().next().getPropertyPath().toString().equals("name")) {
+            return "ko";
+        }
+        return "ok";
+    }
+
+    public static class MyNonEntity {
+        @NotNull
+        public String name;
+    }
+}

extensions/hibernate-orm/deployment/src/test/java/io/quarkus/hibernate/orm/validation/JPATestValidationOfNonEntitiesTestCase.java

@@ -0,0 +1,33 @@
+package io.quarkus.hibernate.orm.validation;
+
+import static org.hamcrest.Matchers.is;
+
+import org.jboss.shrinkwrap.api.asset.StringAsset;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+
+import io.quarkus.hibernate.orm.MyEntity;
+import io.quarkus.test.QuarkusUnitTest;
+import io.restassured.RestAssured;
+
+public class JPATestValidationOfNonEntitiesTestCase {
+
+    @RegisterExtension
+    static QuarkusUnitTest runner = new QuarkusUnitTest()
+            .withApplicationRoot((jar) -> jar
+                    .addClasses(MyEntity.class, JPATestValidationOfNonEntitiesResource.class)
+                    .addAsResource("application.properties")
+                    .addAsResource(new StringAsset(""), "import.sql")); // define an empty import.sql file
+
+    @Test
+    public void testValueValidation() {
+        RestAssured.given().when().get("validation/nonentity/value").then()
+                .body(is("ok"));
+    }
+
+    @Test
+    public void testBeanValidation() {
+        RestAssured.given().when().get("validation/nonentity/bean").then()
+                .body(is("ok"));
+    }
+}

extensions/hibernate-validator/runtime/src/main/java/io/quarkus/hibernate/validator/runtime/HibernateValidatorRecorder.java

@@ -306,6 +306,11 @@ static final class DelegatingTraversableResolver implements TraversableResolver
         @Override
         public boolean isReachable(Object entity, Path.Node traversableProperty, Class<?> rootBeanType,
                 Path pathToTraversableObject, ElementType elementType) {
+            if (entity == null) {
+                // The entity can be null if we are validating values, as that's when the validation context does not have the root object,
+                //  In other cases we shouldn't even reach the traversable resolver when the validated bean/entity is null.
+                return true;
+            }
             return attributeLoadedPredicate.test(entity, traversableProperty.getName());
         }