[#2873] Test flush before running a native quer

And test native queries without entities.

Author: DavideD

hibernate-reactive-core/src/test/java/org/hibernate/reactive/NoEntitiesTest.java

@@ -0,0 +1,63 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.reactive;
+
+import org.hibernate.FlushMode;
+
+import org.junit.jupiter.api.Test;
+
+import io.vertx.junit5.VertxTestContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class NoEntitiesTest extends BaseReactiveTest {
+
+	@Test
+	public void emptyMetamodelWithMutiny() {
+		assertThat( getMutinySessionFactory().getMetamodel().getEntities() ).isEmpty();
+	}
+
+	@Test
+	public void shouldBeAbleToRunQueryWithMutinyTransaction(VertxTestContext context) {
+		test( context, getMutinySessionFactory()
+				.withTransaction( s -> s
+						.createNativeQuery( "select 42", Long.class ).getSingleResult()
+				).invoke( result -> assertThat( result ).isEqualTo( 42L ) )
+		);
+	}
+
+	@Test
+	public void runNativeQueryWithMutinyTransactionAndFlush(VertxTestContext context) {
+		test( context, getMutinySessionFactory()
+				.withTransaction( s -> {
+					s.setFlushMode( FlushMode.ALWAYS );
+					return s
+							.createNativeQuery( "select 42", Long.class ).getSingleResult()
+							.call( s::flush );
+				} ).invoke( result -> assertThat( result ).isEqualTo( 42L ) )
+		);
+	}
+
+	@Test
+	public void runStatelessNativeQueryWithMutinyTransactionAndFlush(VertxTestContext context) {
+		test(
+				context, getMutinySessionFactory()
+						.withStatelessTransaction( s -> s
+								.createNativeQuery( "select 42", Long.class )
+								.getSingleResult()
+						)
+						.invoke( result -> assertThat( result ).isEqualTo( 42L ) )
+		);
+	}
+
+	@Test
+	public void shouldBeAbleToRunQueryWithMutinyWithoutTransaction(VertxTestContext context) {
+		test( context, getMutinySessionFactory()
+				.openSession().chain( s -> s
+						.createNativeQuery( "select 666", Long.class ).getSingleResult()
+				).invoke( result -> assertThat( result ).isEqualTo( 666L ) )
+		);
+	}
+}