/*

 * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

/*

 * @test

 * @bug 8009736 8010279

 * @run testng BasicTest

 */

import java.util.Comparator;

import java.util.function.BinaryOperator;

import java.util.function.Function;

import java.util.function.ToIntFunction;

import org.testng.annotations.Test;

import static java.util.function.BinaryOperator.minBy;

import static java.util.function.BinaryOperator.maxBy;

import static org.testng.Assert.assertSame;

import static org.testng.Assert.fail;

/**

 * Unit tests for helper methods in Comparators

 */

@Test(groups = "unit")

public class BasicTest {

    private static class People {

        final String firstName;

        final String lastName;

        final int age;

        People(String first, String last, int age) {

            firstName = first;

            lastName = last;

            this.age = age;

        }

        String getFirstName() { return firstName; }

        String getLastName() { return lastName; }

        int getAge() { return age; }

    }

    private final People people[] = {

        new People("John", "Doe", 34),

        new People("Mary", "Doe", 30),

    };

    public void testMaxBy() {

        Comparator<People> cmp = Comparator.comparing(People::getFirstName);

        // lesser

        assertSame(maxBy(cmp).apply(people[0], people[1]), people[1]);

        // euqal

        cmp = Comparator.comparing(People::getLastName);

        assertSame(maxBy(cmp).apply(people[0], people[1]), people[0]);

        // greater

        cmp = Comparator.comparingInt(People::getAge);

        assertSame(maxBy(cmp).apply(people[0], people[1]), people[0]);

    }

    public void testMinBy() {

        Comparator<People> cmp = Comparator.comparing(People::getFirstName);

        // lesser

        assertSame(minBy(cmp).apply(people[0], people[1]), people[0]);

        // euqal

        cmp = Comparator.comparing(People::getLastName);

        assertSame(minBy(cmp).apply(people[0], people[1]), people[0]);

        // greater

        cmp = Comparator.comparingInt(People::getAge);

        assertSame(minBy(cmp).apply(people[0], people[1]), people[1]);

    }

    public void testNulls() {

        try {

            BinaryOperator<String> op = minBy(null);

            fail("minBy(null) should throw NPE");

        } catch (NullPointerException npe) {}

        try {

            BinaryOperator<String> op = maxBy(null);

            fail("maxBy(null) should throw NPE");

        } catch (NullPointerException npe) {}

    }

}