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

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

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 * accompanied this code).

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/* @test

 * @bug 8139885

 * @bug 8143798

 * @run testng/othervm -ea -esa test.java.lang.invoke.SpreadCollectTest

 */

package test.java.lang.invoke;

import java.io.StringWriter;

import java.lang.invoke.MethodHandle;

import java.lang.invoke.MethodHandles;

import java.lang.invoke.MethodHandles.Lookup;

import java.lang.invoke.MethodType;

import java.lang.invoke.WrongMethodTypeException;

import java.util.*;

import static java.lang.invoke.MethodType.methodType;

import static org.testng.AssertJUnit.*;

import org.testng.annotations.*;

/**

 * Tests for the new asSpreader/asCollector API added in JEP 274.

 */

public class SpreadCollectTest {

    static final Lookup LOOKUP = MethodHandles.lookup();

    @Test

    public static void testAsSpreader() throws Throwable {

        MethodHandle spreader = SpreadCollect.MH_forSpreading.asSpreader(1, int[].class, 3);

        assertEquals(SpreadCollect.MT_spreader, spreader.type());

        assertEquals("A456B", (String) spreader.invoke("A", new int[]{4, 5, 6}, "B"));

    }

    @Test

    public static void testAsSpreaderExample() throws Throwable {

        // test the JavaDoc asSpreader-with-pos example

        MethodHandle compare = LOOKUP.findStatic(Objects.class, "compare", methodType(int.class, Object.class, Object.class, Comparator.class));

        MethodHandle compare2FromArray = compare.asSpreader(0, Object[].class, 2);

        Object[] ints = new Object[]{3, 9, 7, 7};

        Comparator<Integer> cmp = (a, b) -> a - b;

        assertTrue((int) compare2FromArray.invoke(Arrays.copyOfRange(ints, 0, 2), cmp) < 0);

        assertTrue((int) compare2FromArray.invoke(Arrays.copyOfRange(ints, 1, 3), cmp) > 0);

        assertTrue((int) compare2FromArray.invoke(Arrays.copyOfRange(ints, 2, 4), cmp) == 0);

    }

    @DataProvider

    static Object[][] asSpreaderIllegalPositions() {

        return new Object[][]{{-7}, {3}, {19}};

    }

    @Test(dataProvider = "asSpreaderIllegalPositions")

    public static void testAsSpreaderIllegalPos(int p) throws Throwable {

        boolean caught = false;

        try {

            SpreadCollect.MH_forSpreading.asSpreader(p, Object[].class, 3);

        } catch (IllegalArgumentException iae) {

            assertEquals("bad spread position", iae.getMessage());

            caught = true;

        }

        assertTrue(caught);

    }

    @Test(expectedExceptions = {WrongMethodTypeException.class})

    public static void testAsSpreaderIllegalMethodType() {

        MethodHandle h = MethodHandles.dropArguments(MethodHandles.constant(String.class, ""), 0, int.class, int.class);

        MethodHandle s = h.asSpreader(String[].class, 1);

    }

    @Test

    public static void testAsCollector() throws Throwable {

        MethodHandle collector = SpreadCollect.MH_forCollecting.asCollector(1, int[].class, 1);

        assertEquals(SpreadCollect.MT_collector1, collector.type());

        assertEquals("A4B", (String) collector.invoke("A", 4, "B"));

        collector = SpreadCollect.MH_forCollecting.asCollector(1, int[].class, 2);

        assertEquals(SpreadCollect.MT_collector2, collector.type());

        assertEquals("A45B", (String) collector.invoke("A", 4, 5, "B"));

        collector = SpreadCollect.MH_forCollecting.asCollector(1, int[].class, 3);

        assertEquals(SpreadCollect.MT_collector3, collector.type());

        assertEquals("A456B", (String) collector.invoke("A", 4, 5, 6, "B"));

    }

    @Test

    public static void testAsCollectorInvokeWithArguments() throws Throwable {

        MethodHandle collector = SpreadCollect.MH_forCollecting.asCollector(1, int[].class, 1);

        assertEquals(SpreadCollect.MT_collector1, collector.type());

        assertEquals("A4B", (String) collector.invokeWithArguments("A", 4, "B"));

        collector = SpreadCollect.MH_forCollecting.asCollector(1, int[].class, 2);

        assertEquals(SpreadCollect.MT_collector2, collector.type());

        assertEquals("A45B", (String) collector.invokeWithArguments("A", 4, 5, "B"));

        collector = SpreadCollect.MH_forCollecting.asCollector(1, int[].class, 3);

        assertEquals(SpreadCollect.MT_collector3, collector.type());

        assertEquals("A456B", (String) collector.invokeWithArguments("A", 4, 5, 6, "B"));

    }

    @Test

    public static void testAsCollectorLeading() throws Throwable {

        MethodHandle collector = SpreadCollect.MH_forCollectingLeading.asCollector(0, int[].class, 1);

        assertEquals(SpreadCollect.MT_collectorLeading1, collector.type());

        assertEquals("7Q", (String) collector.invoke(7, "Q"));

        collector = SpreadCollect.MH_forCollectingLeading.asCollector(0, int[].class, 2);

        assertEquals(SpreadCollect.MT_collectorLeading2, collector.type());

        assertEquals("78Q", (String) collector.invoke(7, 8, "Q"));

        collector = SpreadCollect.MH_forCollectingLeading.asCollector(0, int[].class, 3);

        assertEquals(SpreadCollect.MT_collectorLeading3, collector.type());

        assertEquals("789Q", (String) collector.invoke(7, 8, 9, "Q"));

    }

    @Test

    public static void testAsCollectorLeadingInvokeWithArguments() throws Throwable {

        MethodHandle collector = SpreadCollect.MH_forCollectingLeading.asCollector(0, int[].class, 1);

        assertEquals(SpreadCollect.MT_collectorLeading1, collector.type());

        assertEquals("7Q", (String) collector.invokeWithArguments(7, "Q"));

        collector = SpreadCollect.MH_forCollectingLeading.asCollector(0, int[].class, 2);

        assertEquals(SpreadCollect.MT_collectorLeading2, collector.type());

        assertEquals("78Q", (String) collector.invokeWithArguments(7, 8, "Q"));

        collector = SpreadCollect.MH_forCollectingLeading.asCollector(0, int[].class, 3);

        assertEquals(SpreadCollect.MT_collectorLeading3, collector.type());

        assertEquals("789Q", (String) collector.invokeWithArguments(7, 8, 9, "Q"));

    }

    @Test

    public static void testAsCollectorNone() throws Throwable {

        MethodHandle collector = SpreadCollect.MH_forCollecting.asCollector(1, int[].class, 0);

        assertEquals(SpreadCollect.MT_collector0, collector.type());

        assertEquals("AB", (String) collector.invoke("A", "B"));

    }

    @DataProvider

    static Object[][] asCollectorIllegalPositions() {

        return new Object[][]{{-1}, {17}};

    }

    @Test(dataProvider = "asCollectorIllegalPositions")

    public static void testAsCollectorIllegalPos(int p) {

        boolean caught = false;

        try {

            SpreadCollect.MH_forCollecting.asCollector(p, int[].class, 0);

        } catch (IllegalArgumentException iae) {

            assertEquals("bad collect position", iae.getMessage());

            caught = true;

        }

        assertTrue(caught);

    }

    @Test

    public static void testAsCollectorExample() throws Throwable {

        // test the JavaDoc asCollector-with-pos example

        StringWriter swr = new StringWriter();

        MethodHandle swWrite = LOOKUP.

                findVirtual(StringWriter.class, "write", methodType(void.class, char[].class, int.class, int.class)).

                bindTo(swr);

        MethodHandle swWrite4 = swWrite.asCollector(0, char[].class, 4);

        swWrite4.invoke('A', 'B', 'C', 'D', 1, 2);

        assertEquals("BC", swr.toString());

        swWrite4.invoke('P', 'Q', 'R', 'S', 0, 4);

        assertEquals("BCPQRS", swr.toString());

        swWrite4.invoke('W', 'X', 'Y', 'Z', 3, 1);

        assertEquals("BCPQRSZ", swr.toString());

    }

    static class SpreadCollect {

        static String forSpreading(String s1, int i1, int i2, int i3, String s2) {

            return s1 + i1 + i2 + i3 + s2;

        }

        static String forCollecting(String s1, int[] is, String s2) {

            StringBuilder sb = new StringBuilder(s1);

            for (int i : is) {

                sb.append(i);

            }

            return sb.append(s2).toString();

        }

        static String forCollectingLeading(int[] is, String s) {

            return forCollecting("", is, s);

        }

        static final Class<SpreadCollect> SPREAD_COLLECT = SpreadCollect.class;

        static final MethodType MT_forSpreading = methodType(String.class, String.class, int.class, int.class, int.class, String.class);

        static final MethodType MT_forCollecting = methodType(String.class, String.class, int[].class, String.class);

        static final MethodType MT_forCollectingLeading = methodType(String.class, int[].class, String.class);

        static final MethodHandle MH_forSpreading;

        static final MethodHandle MH_forCollecting;

        static final MethodHandle MH_forCollectingLeading;

        static final MethodType MT_spreader = methodType(String.class, String.class, int[].class, String.class);

        static final MethodType MT_collector0 = methodType(String.class, String.class, String.class);

        static final MethodType MT_collector1 = methodType(String.class, String.class, int.class, String.class);

        static final MethodType MT_collector2 = methodType(String.class, String.class, int.class, int.class, String.class);

        static final MethodType MT_collector3 = methodType(String.class, String.class, int.class, int.class, int.class, String.class);

        static final MethodType MT_collectorLeading1 = methodType(String.class, int.class, String.class);

        static final MethodType MT_collectorLeading2 = methodType(String.class, int.class, int.class, String.class);

        static final MethodType MT_collectorLeading3 = methodType(String.class, int.class, int.class, int.class, String.class);

        static final String NONE_ERROR = "zero array length in MethodHandle.asCollector";

        static {

            try {

                MH_forSpreading = LOOKUP.findStatic(SPREAD_COLLECT, "forSpreading", MT_forSpreading);

                MH_forCollecting = LOOKUP.findStatic(SPREAD_COLLECT, "forCollecting", MT_forCollecting);

                MH_forCollectingLeading = LOOKUP.findStatic(SPREAD_COLLECT, "forCollectingLeading", MT_forCollectingLeading);

            } catch (Exception e) {

                throw new ExceptionInInitializerError(e);

            }

        }

    }

}