HHH-18377 Test cases to check monofonicity of generated version 6 & version 7 UUID's

Author: cigaly

hibernate-core/src/test/java/org/hibernate/orm/test/id/uuid/rfc9562/UUidV6V7GenetartorTest.java

@@ -0,0 +1,43 @@
+package org.hibernate.orm.test.id.uuid.rfc9562;
+
+import java.util.UUID;
+
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.id.uuid.UuidV6ValueGenerator;
+import org.hibernate.id.uuid.UuidV7ValueGenerator;
+import org.hibernate.id.uuid.UuidValueGenerator;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+public class UUidV6V7GenetartorTest {
+
+	private static final UUID NIL_UUID = new UUID( 0L, 0L );
+	private static final int ITERATIONS = 1_000_000;
+
+	@Test
+	void testMonotonicityUuid6() {
+		testMonotonicity( new UuidV6ValueGenerator() );
+	}
+
+	@Test
+	void testMonotonicityUuid7() {
+		testMonotonicity( new UuidV7ValueGenerator() );
+	}
+
+	private static void testMonotonicity(UuidValueGenerator generator) {
+		final SharedSessionContractImplementor session = mock( SharedSessionContractImplementor.class );
+		final UUID[] uuids = new UUID[ITERATIONS + 1];
+		uuids[0] = NIL_UUID;
+		for ( int n = 1; n <= ITERATIONS; ++n ) {
+			uuids[n] = generator.generateUuid( session );
+		}
+
+		for ( var n = 0; n < ITERATIONS; ++n ) {
+			assertThat( uuids[n + 1].toString() ).isGreaterThan( uuids[n].toString() );
+			assertThat( uuids[n + 1] ).isGreaterThan( uuids[n] );
+		}
+	}
+}