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/**

 * @test

 * @library /lib/testlibrary

 * @build BasicLayerTest ModuleUtils

 * @compile layertest/Test.java

 * @run testng BasicLayerTest

 * @summary Basic tests for java.lang.reflect.Layer

 */

import java.lang.module.Configuration;

import java.lang.module.ModuleDescriptor;

import java.lang.module.ModuleDescriptor.Requires;

import java.lang.module.ModuleFinder;

import java.lang.reflect.Layer;

import java.lang.reflect.LayerInstantiationException;

import java.lang.reflect.Module;

import java.util.HashMap;

import java.util.Map;

import java.util.Optional;

import java.util.Set;

import java.util.stream.Collectors;

import org.testng.annotations.Test;

import static org.testng.Assert.*;

@Test

public class BasicLayerTest {

    /**

     * Exercise Layer.empty()

     */

    public void testEmpty() {

        Layer emptyLayer = Layer.empty();

        assertTrue(emptyLayer.parents().isEmpty());

        assertTrue(emptyLayer.configuration() == Configuration.empty());

        assertTrue(emptyLayer.modules().isEmpty());

        assertFalse(emptyLayer.findModule("java.base").isPresent());

        try {

            emptyLayer.findLoader("java.base");

            assertTrue(false);

        } catch (IllegalArgumentException expected) { }

    }

    /**

     * Exercise Layer.boot()

     */

    public void testBoot() {

        Layer bootLayer = Layer.boot();

        // configuration

        Configuration cf = bootLayer.configuration();

        assertTrue(cf.findModule("java.base").get()

                .reference()

                .descriptor()

                .exports()

                .stream().anyMatch(e -> (e.source().equals("java.lang")

                                         && !e.isQualified())));

        // modules

        Set<Module> modules = bootLayer.modules();

        assertTrue(modules.contains(Object.class.getModule()));

        int count = (int) modules.stream().map(Module::getName).count();

        assertEquals(count, modules.size()); // module names are unique

        // findModule

        Module base = Object.class.getModule();

        assertTrue(bootLayer.findModule("java.base").get() == base);

        assertTrue(base.getLayer() == bootLayer);

        // findLoader

        assertTrue(bootLayer.findLoader("java.base") == null);

        // parents

        assertTrue(bootLayer.parents().size() == 1);

        assertTrue(bootLayer.parents().get(0) == Layer.empty());

    }

    /**

     * Exercise Layer defineModules, created with empty layer as parent

     */

    public void testLayerOnEmpty() {

                .requires("m2")

                .exports("p1")

                .build();

                .requires("m3")

                .build();

                .build();

        ModuleFinder finder

            = ModuleUtils.finderOf(descriptor1, descriptor2, descriptor3);

        // map each module to its own class loader for this test

        ClassLoader loader1 = new ClassLoader() { };

        ClassLoader loader2 = new ClassLoader() { };

        ClassLoader loader3 = new ClassLoader() { };

        Map<String, ClassLoader> map = new HashMap<>();

        map.put("m1", loader1);

        map.put("m2", loader2);

        map.put("m3", loader3);

        Layer layer = Layer.empty().defineModules(cf, map::get);

        // configuration

        assertTrue(layer.configuration() == cf);

        assertTrue(layer.configuration().modules().size() == 3);

        // modules

        Set<Module> modules = layer.modules();

        assertTrue(modules.size() == 3);

        Set<String> names = modules.stream()

            .map(Module::getName)

            .collect(Collectors.toSet());

        assertTrue(names.contains("m1"));

        assertTrue(names.contains("m2"));

        assertTrue(names.contains("m3"));

        // findModule

        Module m1 = layer.findModule("m1").get();

        Module m2 = layer.findModule("m2").get();

        Module m3 = layer.findModule("m3").get();

        assertEquals(m1.getName(), "m1");

        assertEquals(m2.getName(), "m2");

        assertEquals(m3.getName(), "m3");

        assertTrue(m1.getDescriptor() == descriptor1);

        assertTrue(m2.getDescriptor() == descriptor2);

        assertTrue(m3.getDescriptor() == descriptor3);

        assertTrue(m1.getLayer() == layer);

        assertTrue(m2.getLayer() == layer);

        assertTrue(m3.getLayer() == layer);

        assertTrue(modules.contains(m1));

        assertTrue(modules.contains(m2));

        assertTrue(modules.contains(m3));

        assertFalse(layer.findModule("godot").isPresent());

        // findLoader

        assertTrue(layer.findLoader("m1") == loader1);

        assertTrue(layer.findLoader("m2") == loader2);

        assertTrue(layer.findLoader("m3") == loader3);

        try {

            ClassLoader loader = layer.findLoader("godot");

            assertTrue(false);

        } catch (IllegalArgumentException ignore) { }

        // parents

        assertTrue(layer.parents().size() == 1);

        assertTrue(layer.parents().get(0) == Layer.empty());

    }

    /**

     * Exercise Layer defineModules, created with boot layer as parent

     */

    public void testLayerOnBoot() {

                .requires("m2")

                .requires("java.base")

                .exports("p1")

                .build();

                .requires("java.base")

                .build();

        ModuleFinder finder

            = ModuleUtils.finderOf(descriptor1, descriptor2);

        Configuration parent = Layer.boot().configuration();

        ClassLoader loader = new ClassLoader() { };

        Layer layer = Layer.boot().defineModules(cf, mn -> loader);

        // configuration

        assertTrue(layer.configuration() == cf);

        assertTrue(layer.configuration().modules().size() == 2);

        // modules

        Set<Module> modules = layer.modules();

        assertTrue(modules.size() == 2);

        Set<String> names = modules.stream()

            .map(Module::getName)

            .collect(Collectors.toSet());

        assertTrue(names.contains("m1"));

        assertTrue(names.contains("m2"));

        // findModule

        Module m1 = layer.findModule("m1").get();

        Module m2 = layer.findModule("m2").get();

        assertEquals(m1.getName(), "m1");

        assertEquals(m2.getName(), "m2");

        assertTrue(m1.getDescriptor() == descriptor1);

        assertTrue(m2.getDescriptor() == descriptor2);

        assertTrue(m1.getLayer() == layer);

        assertTrue(m2.getLayer() == layer);

        assertTrue(modules.contains(m1));

        assertTrue(modules.contains(m2));

        assertTrue(layer.findModule("java.base").get() == Object.class.getModule());

        assertFalse(layer.findModule("godot").isPresent());

        // findLoader

        assertTrue(layer.findLoader("m1") == loader);

        assertTrue(layer.findLoader("m2") == loader);

        assertTrue(layer.findLoader("java.base") == null);

        // parents

        assertTrue(layer.parents().size() == 1);

        assertTrue(layer.parents().get(0) == Layer.boot());

    }

    /**

     * Exercise Layer defineModules with a configuration of two modules that

     * have the same module-private package.

     */

    public void testPackageContainedInSelfAndOther() {

                .requires("m2")

                .build();

                .build();

        ModuleFinder finder

            = ModuleUtils.finderOf(descriptor1, descriptor2);

        assertTrue(cf.modules().size() == 2);

        // one loader per module, should be okay

        Layer.empty().defineModules(cf, mn -> new ClassLoader() { });

        // same class loader

        try {

            ClassLoader loader = new ClassLoader() { };

            Layer.empty().defineModules(cf, mn -> loader);

            assertTrue(false);

        } catch (LayerInstantiationException expected) { }

    }

    /**

     * Exercise Layer defineModules with a configuration that is a partitioned

     * graph. The same package is exported in both partitions.

     */

    public void testSameExportInPartitionedGraph() {

        // m1 reads m2, m2 exports p to m1

                .requires("m2")

                .build();

                .exports("p", Set.of("m1"))

                .build();

        // m3 reads m4, m4 exports p to m3

                .requires("m4")

                .build();

                .exports("p", Set.of("m3"))

                .build();

        ModuleFinder finder

            = ModuleUtils.finderOf(descriptor1,

                                   descriptor2,

                                   descriptor3,

                                   descriptor4);

        assertTrue(cf.modules().size() == 4);

        // one loader per module

        Layer.empty().defineModules(cf, mn -> new ClassLoader() { });

        // m1 & m2 in one loader, m3 & m4 in another loader

        ClassLoader loader1 = new ClassLoader() { };

        ClassLoader loader2 = new ClassLoader() { };

        Map<String, ClassLoader> map = new HashMap<>();

        map.put("m1", loader1);

        map.put("m2", loader1);

        map.put("m3", loader2);

        map.put("m4", loader2);

        Layer.empty().defineModules(cf, map::get);

        // same loader

        try {

            ClassLoader loader = new ClassLoader() { };

            Layer.empty().defineModules(cf, mn -> loader);

            assertTrue(false);

        } catch (LayerInstantiationException expected) { }

    }

    /**

     * Exercise Layer defineModules with a configuration with a module that

     * contains a package that is the same name as a non-exported package in

     * a parent layer.

     */

    public void testContainsSamePackageAsBootLayer() {

        // check assumption that java.base contains sun.launcher

        ModuleDescriptor base = Object.class.getModule().getDescriptor();

        assertTrue(base.packages().contains("sun.launcher"));

               .requires("java.base")

               .build();

        ModuleFinder finder = ModuleUtils.finderOf(descriptor);

        Configuration parent = Layer.boot().configuration();

        assertTrue(cf.modules().size() == 1);

        ClassLoader loader = new ClassLoader() { };

        Layer layer = Layer.boot().defineModules(cf, mn -> loader);

        assertTrue(layer.modules().size() == 1);

   }

    /**

     * Test layers with implied readability.

     *

     * The test consists of three configurations:

     * - Configuration/layer1: m1, m2 requires transitive m1

     * - Configuration/layer2: m3 requires m1

     */

    public void testImpliedReadabilityWithLayers1() {

        // cf1: m1 and m2, m2 requires transitive m1

                .build();

                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m1")

                .build();

        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1, descriptor2);

        ClassLoader cl1 = new ClassLoader() { };

        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);

        // cf2: m3, m3 requires m2

                .requires("m2")

                .build();

        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor3);

        ClassLoader cl2 = new ClassLoader() { };

        Layer layer2 = layer1.defineModules(cf2, mn -> cl2);

        assertTrue(layer1.parents().size() == 1);

        assertTrue(layer1.parents().get(0) == Layer.empty());

        assertTrue(layer2.parents().size() == 1);

        assertTrue(layer2.parents().get(0) == layer1);

        Module m1 = layer2.findModule("m1").get();

        Module m2 = layer2.findModule("m2").get();

        Module m3 = layer2.findModule("m3").get();

        assertTrue(m1.getLayer() == layer1);

        assertTrue(m2.getLayer() == layer1);

        assertTrue(m3.getLayer() == layer2);

        assertTrue(m1.getClassLoader() == cl1);

        assertTrue(m2.getClassLoader() == cl1);

        assertTrue(m3.getClassLoader() == cl2);

        assertTrue(m1.canRead(m1));

        assertFalse(m1.canRead(m2));

        assertFalse(m1.canRead(m3));

        assertTrue(m2.canRead(m1));

        assertTrue(m2.canRead(m2));

        assertFalse(m2.canRead(m3));

        assertTrue(m3.canRead(m1));

        assertTrue(m3.canRead(m2));

        assertTrue(m3.canRead(m3));

    }

    /**

     * Test layers with implied readability.

     *

     * The test consists of three configurations:

     * - Configuration/layer1: m1

     * - Configuration/layer2: m2 requires transitive m3, m3 requires m2

     */

    public void testImpliedReadabilityWithLayers2() {

        // cf1: m1

        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1);

        ClassLoader cl1 = new ClassLoader() { };

        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);

        // cf2: m2, m3: m2 requires transitive m1, m3 requires m2

                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m1")

                .build();

                .requires("m2")

                .build();

        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor2, descriptor3);

        ClassLoader cl2 = new ClassLoader() { };

        Layer layer2 = layer1.defineModules(cf2, mn -> cl2);

        assertTrue(layer1.parents().size() == 1);

        assertTrue(layer1.parents().get(0) == Layer.empty());

        assertTrue(layer2.parents().size() == 1);

        assertTrue(layer2.parents().get(0) == layer1);

        Module m1 = layer2.findModule("m1").get();

        Module m2 = layer2.findModule("m2").get();

        Module m3 = layer2.findModule("m3").get();

        assertTrue(m1.getLayer() == layer1);

        assertTrue(m2.getLayer() == layer2);

        assertTrue(m3.getLayer() == layer2);

        assertTrue(m1.canRead(m1));

        assertFalse(m1.canRead(m2));

        assertFalse(m1.canRead(m3));

        assertTrue(m2.canRead(m1));

        assertTrue(m2.canRead(m2));

        assertFalse(m2.canRead(m3));

        assertTrue(m3.canRead(m1));

        assertTrue(m3.canRead(m2));

        assertTrue(m3.canRead(m3));

    }

    /**

     * Test layers with implied readability.

     *

     * The test consists of three configurations:

     * - Configuration/layer1: m1

     * - Configuration/layer2: m2 requires transitive m1