1 /*
 2  * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.
 8  *
 9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 import org.testng.Assert;
25 import org.testng.annotations.Test;
26 
27 import java.lang.invoke.MethodHandles;
28 import java.lang.reflect.code.interpreter.Interpreter;
29 import java.util.stream.Stream;
30 
31 /*
32  * @test
33  * @enablePreview
34  * @run testng TestLinq
35  */
36 
37 public class TestLinq {
38 
39     // A record modeling a table with three columns, one for each component
40     record Customer(String contactName, String phone, String city) {
41     }
42 
43     @Test
44     public void testSimpleQuery() {
45         QueryProvider qp = new TestQueryProvider();
46 
47         // Query all customers based in London, and return their names
48         QueryResult<Stream<String>> qr = qp.query(Customer.class)
49                 .where(c -> c.city.equals("London"))
50                 .select(c -> c.contactName)
51                 .elements();
52 
53         System.out.println(qr.expression().toText());
54 
55         @SuppressWarnings("unchecked")
56         QueryResult<Stream<String>> qr2 = (QueryResult<Stream<String>>) Interpreter.invoke(MethodHandles.lookup(),
57                 qr.expression(), qp.query(Customer.class));
58         System.out.println(qr2.expression().toText());
59 
60         Assert.assertEquals(qr.expression().toText(), qr2.expression().toText());
61     }
62 }