jdk/test/java/lang/reflect/Layer/BasicLayerTest.java
changeset 44545 83b611b88ac8
parent 44480 2c33418a6d57
child 44546 10bdbc025c7f
--- a/jdk/test/java/lang/reflect/Layer/BasicLayerTest.java	Thu Apr 06 17:01:03 2017 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1219 +0,0 @@
-/*
- * Copyright (c) 2014, 2017, 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
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-/**
- * @test
- * @library /lib/testlibrary
- * @modules java.base/jdk.internal.misc
- * @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 jdk.internal.misc.SharedSecrets;
-
-import org.testng.annotations.DataProvider;
-import org.testng.annotations.Test;
-import static org.testng.Assert.*;
-
-@Test
-public class BasicLayerTest {
-
-    /**
-     * Creates a "non-strict" builder for building a module. This allows the
-     * test the create ModuleDescriptor objects that do not require java.base.
-     */
-    private static ModuleDescriptor.Builder newBuilder(String mn) {
-        return SharedSecrets.getJavaLangModuleAccess()
-                .newModuleBuilder(mn, false, Set.of());
-    }
-
-    /**
-     * 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() {
-        ModuleDescriptor descriptor1 = newBuilder("m1")
-                .requires("m2")
-                .exports("p1")
-                .build();
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires("m3")
-                .build();
-
-        ModuleDescriptor descriptor3 = newBuilder("m3")
-                .build();
-
-        ModuleFinder finder
-            = ModuleUtils.finderOf(descriptor1, descriptor2, descriptor3);
-
-        Configuration cf = resolve(finder, "m1");
-
-        // 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() {
-        ModuleDescriptor descriptor1 = newBuilder("m1")
-                .requires("m2")
-                .requires("java.base")
-                .exports("p1")
-                .build();
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires("java.base")
-                .build();
-
-        ModuleFinder finder
-            = ModuleUtils.finderOf(descriptor1, descriptor2);
-
-        Configuration parent = Layer.boot().configuration();
-        Configuration cf = resolve(parent, finder, "m1");
-
-        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() {
-        ModuleDescriptor descriptor1 =  newBuilder("m1")
-                .requires("m2")
-                .packages(Set.of("p"))
-                .build();
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .packages(Set.of("p"))
-                .build();
-
-        ModuleFinder finder
-            = ModuleUtils.finderOf(descriptor1, descriptor2);
-
-        Configuration cf = resolve(finder, "m1");
-        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
-        ModuleDescriptor descriptor1 =  newBuilder("m1")
-                .requires("m2")
-                .build();
-        ModuleDescriptor descriptor2 =  newBuilder("m2")
-                .exports("p", Set.of("m1"))
-                .build();
-
-        // m3 reads m4, m4 exports p to m3
-        ModuleDescriptor descriptor3 = newBuilder("m3")
-                .requires("m4")
-                .build();
-        ModuleDescriptor descriptor4 = newBuilder("m4")
-                .exports("p", Set.of("m3"))
-                .build();
-
-        ModuleFinder finder
-            = ModuleUtils.finderOf(descriptor1,
-                                   descriptor2,
-                                   descriptor3,
-                                   descriptor4);
-
-        Configuration cf = resolve(finder, "m1", "m3");
-        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"));
-
-        ModuleDescriptor descriptor = newBuilder("m1")
-               .requires("java.base")
-               .packages(Set.of("sun.launcher"))
-               .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(descriptor);
-
-        Configuration parent = Layer.boot().configuration();
-        Configuration cf = parent.resolve(finder, ModuleFinder.of(), Set.of("m1"));
-        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
-
-        ModuleDescriptor descriptor1 = newBuilder("m1")
-                .build();
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m1")
-                .build();
-
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1, descriptor2);
-
-        Configuration cf1 = resolve(finder1, "m2");
-
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-
-
-        // cf2: m3, m3 requires m2
-
-        ModuleDescriptor descriptor3 = newBuilder("m3")
-                .requires("m2")
-                .build();
-
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor3);
-
-        Configuration cf2 = resolve(cf1, finder2, "m3");
-
-        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
-
-        ModuleDescriptor descriptor1 = newBuilder("m1").build();
-
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1);
-
-        Configuration cf1 = resolve(finder1, "m1");
-
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-
-
-        // cf2: m2, m3: m2 requires transitive m1, m3 requires m2
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m1")
-                .build();
-
-        ModuleDescriptor descriptor3 = newBuilder("m3")
-                .requires("m2")
-                .build();
-
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor2, descriptor3);
-
-        Configuration cf2 = resolve(cf1, finder2, "m3");
-
-        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
-     * - Configuration/layer3: m3 requires m1
-     */
-    public void testImpliedReadabilityWithLayers3() {
-
-        // cf1: m1
-
-        ModuleDescriptor descriptor1 = newBuilder("m1").build();
-
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1);
-
-        Configuration cf1 = resolve(finder1, "m1");
-
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-
-
-        // cf2: m2 requires transitive m1
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m1")
-                .build();
-
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor2);
-
-        Configuration cf2 = resolve(cf1, finder2, "m2");
-
-        ClassLoader cl2 = new ClassLoader() { };
-        Layer layer2 = layer1.defineModules(cf2, mn -> cl2);
-
-
-        // cf3: m3 requires m2
-
-        ModuleDescriptor descriptor3 = newBuilder("m3")
-                .requires("m2")
-                .build();
-
-        ModuleFinder finder3 = ModuleUtils.finderOf(descriptor3);
-
-        Configuration cf3 = resolve(cf2, finder3, "m3");
-
-        ClassLoader cl3 = new ClassLoader() { };
-        Layer layer3 = layer2.defineModules(cf3, mn -> cl3);
-
-        assertTrue(layer1.parents().size() == 1);
-        assertTrue(layer1.parents().get(0) == Layer.empty());
-
-        assertTrue(layer2.parents().size() == 1);
-        assertTrue(layer2.parents().get(0) == layer1);
-
-        assertTrue(layer3.parents().size() == 1);
-        assertTrue(layer3.parents().get(0) == layer2);
-
-        Module m1 = layer3.findModule("m1").get();
-        Module m2 = layer3.findModule("m2").get();
-        Module m3 = layer3.findModule("m3").get();
-
-        assertTrue(m1.getLayer() == layer1);
-        assertTrue(m2.getLayer() == layer2);
-        assertTrue(m3.getLayer() == layer3);
-
-        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 two configurations:
-     * - Configuration/layer1: m1, m2 requires transitive m1
-     * - Configuration/layer2: m3 requires transitive m2, m4 requires m3
-     */
-    public void testImpliedReadabilityWithLayers4() {
-
-        // cf1: m1, m2 requires transitive m1
-
-        ModuleDescriptor descriptor1 = newBuilder("m1")
-                .build();
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m1")
-                .build();
-
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1, descriptor2);
-
-        Configuration cf1 = resolve(finder1, "m2");
-
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-
-
-        // cf2: m3 requires transitive m2, m4 requires m3
-
-        ModuleDescriptor descriptor3 = newBuilder("m3")
-                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m2")
-                .build();
-
-        ModuleDescriptor descriptor4 = newBuilder("m4")
-                .requires("m3")
-                .build();
-
-
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor3, descriptor4);
-
-        Configuration cf2 = resolve(cf1, finder2, "m3", "m4");
-
-        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();
-        Module m4 = layer2.findModule("m4").get();
-
-        assertTrue(m1.getLayer() == layer1);
-        assertTrue(m2.getLayer() == layer1);
-        assertTrue(m3.getLayer() == layer2);
-        assertTrue(m4.getLayer() == layer2);
-
-        assertTrue(m1.canRead(m1));
-        assertFalse(m1.canRead(m2));
-        assertFalse(m1.canRead(m3));
-        assertFalse(m1.canRead(m4));
-
-        assertTrue(m2.canRead(m1));
-        assertTrue(m2.canRead(m2));
-        assertFalse(m1.canRead(m3));
-        assertFalse(m1.canRead(m4));
-
-        assertTrue(m3.canRead(m1));
-        assertTrue(m3.canRead(m2));
-        assertTrue(m3.canRead(m3));
-        assertFalse(m3.canRead(m4));
-
-        assertTrue(m4.canRead(m1));
-        assertTrue(m4.canRead(m2));
-        assertTrue(m4.canRead(m3));
-        assertTrue(m4.canRead(m4));
-    }
-
-
-    /**
-     * Test layers with a qualified export. The module exporting the package
-     * does not read the target module.
-     *
-     * m1 { exports p to m2 }
-     * m2 { }
-     */
-    public void testQualifiedExports1() {
-        ModuleDescriptor descriptor1 = newBuilder("m1").
-                exports("p", Set.of("m2"))
-                .build();
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .build();
-
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1, descriptor2);
-
-        Configuration cf = resolve(finder1, "m1", "m2");
-
-        ClassLoader cl = new ClassLoader() { };
-        Layer layer = Layer.empty().defineModules(cf, mn -> cl);
-        assertTrue(layer.modules().size() == 2);
-
-        Module m1 = layer.findModule("m1").get();
-        Module m2 = layer.findModule("m2").get();
-
-        // check m1 exports p to m2
-        assertFalse(m1.isExported("p"));
-        assertTrue(m1.isExported("p", m2));
-        assertFalse(m1.isOpen("p", m2));
-    }
-
-
-    /**
-     * Test layers with a qualified export. The module exporting the package
-     * reads the target module.
-     *
-     * m1 { exports p to m2; }
-     * m2 { requires m1; }
-     */
-    public void testQualifiedExports2() {
-        ModuleDescriptor descriptor1 = newBuilder("m1")
-                .exports("p", Set.of("m2"))
-                .build();
-
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires("m1")
-                .build();
-
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1, descriptor2);
-
-        Configuration cf = resolve(finder1, "m2");
-        ClassLoader cl = new ClassLoader() { };
-        Layer layer = Layer.empty().defineModules(cf, mn -> cl);
-        assertTrue(layer.modules().size() == 2);
-
-        Module m1 = layer.findModule("m1").get();
-        Module m2 = layer.findModule("m2").get();
-
-        // check m1 exports p to m2
-        assertFalse(m1.isExported("p"));
-        assertTrue(m1.isExported("p", m2));
-        assertFalse(m1.isOpen("p", m2));
-    }
-
-
-    /**
-     * Test layers with a qualified export. The module exporting the package
-     * does not read the target module in the parent layer.
-     *
-     * - Configuration/layer1: m1 { }
-     * - Configuration/layer2: m2 { exports p to m1; }
-     */
-    public void testQualifiedExports3() {
-        // create layer1 with m1
-        ModuleDescriptor descriptor1 = newBuilder("m1").build();
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1);
-        Configuration cf1 = resolve(finder1, "m1");
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-        assertTrue(layer1.modules().size() == 1);
-
-        // create layer2 with m2
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .exports("p", Set.of("m1"))
-                .build();
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor2);
-        Configuration cf2 = resolve(cf1, finder2, "m2");
-        ClassLoader cl2 = new ClassLoader() { };
-        Layer layer2 = layer1.defineModules(cf2, mn -> cl2);
-        assertTrue(layer2.modules().size() == 1);
-
-        Module m1 = layer1.findModule("m1").get();
-        Module m2 = layer2.findModule("m2").get();
-
-        // check m2 exports p to layer1/m1
-        assertFalse(m2.isExported("p"));
-        assertTrue(m2.isExported("p", m1));
-        assertFalse(m2.isOpen("p", m1));
-    }
-
-
-    /**
-     * Test layers with a qualified export. The module exporting the package
-     * reads the target module in the parent layer.
-     *
-     * - Configuration/layer1: m1 { }
-     * - Configuration/layer2: m2 { requires m1; exports p to m1; }
-     */
-    public void testQualifiedExports4() {
-        // create layer1 with m1
-        ModuleDescriptor descriptor1 = newBuilder("m1").build();
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1);
-        Configuration cf1 = resolve(finder1, "m1");
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-        assertTrue(layer1.modules().size() == 1);
-
-        // create layer2 with m2
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires("m1")
-                .exports("p", Set.of("m1"))
-                .build();
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor2);
-        Configuration cf2 = resolve(cf1, finder2, "m2");
-        ClassLoader cl2 = new ClassLoader() { };
-        Layer layer2 = layer1.defineModules(cf2, mn -> cl2);
-        assertTrue(layer2.modules().size() == 1);
-
-        Module m1 = layer1.findModule("m1").get();
-        Module m2 = layer2.findModule("m2").get();
-
-        // check m2 exports p to layer1/m1
-        assertFalse(m2.isExported("p"));
-        assertTrue(m2.isExported("p", m1));
-        assertFalse(m2.isOpen("p", m1));
-    }
-
-    /**
-     * Test layers with a qualified export. The module exporting the package
-     * does not read the target module.
-     *
-     * - Configuration/layer1: m1
-     * - Configuration/layer2: m1, m2 { exports p to m1; }
-     */
-    public void testQualifiedExports5() {
-        // create layer1 with m1
-        ModuleDescriptor descriptor1 = newBuilder("m1").build();
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1);
-        Configuration cf1 = resolve(finder1, "m1");
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-        assertTrue(layer1.modules().size() == 1);
-
-        // create layer2 with m1 and m2
-        ModuleDescriptor descriptor2 = newBuilder("m2").exports("p", Set.of("m1")).build();
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor1, descriptor2);
-        Configuration cf2 = resolve(cf1, finder2, "m1", "m2");
-        ClassLoader cl2 = new ClassLoader() { };
-        Layer layer2 = layer1.defineModules(cf2, mn -> cl2);
-        assertTrue(layer2.modules().size() == 2);
-
-        Module m1_v1 = layer1.findModule("m1").get();
-        Module m1_v2 = layer2.findModule("m1").get();
-        Module m2 = layer2.findModule("m2").get();
-
-        // check m2 exports p to layer2/m2
-        assertFalse(m2.isExported("p"));
-        assertTrue(m2.isExported("p", m1_v2));
-        assertFalse(m2.isExported("p", m1_v1));
-    }
-
-
-    /**
-     * Test layers with a qualified export. The module exporting the package
-     * reads the target module in the parent layer (due to requires transitive).
-     *
-     * - Configuration/layer1: m1, m2 { requires transitive m1; }
-     * - Configuration/layer2: m1, m3 { requires m2; exports p to m1; }
-     */
-    public void testQualifiedExports6() {
-        // create layer1 with m1 and m2
-        ModuleDescriptor descriptor1 = newBuilder("m1").build();
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .requires(Set.of(Requires.Modifier.TRANSITIVE), "m1")
-                .build();
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1, descriptor2);
-        Configuration cf1 = resolve(finder1, "m2");
-        ClassLoader loader1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> loader1);
-        assertTrue(layer1.modules().size() == 2);
-
-        // create layer2 with m1 and m3
-        ModuleDescriptor descriptor3 = newBuilder("m3")
-                .requires("m2")
-                .exports("p", Set.of("m1"))
-                .build();
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor1, descriptor3);
-        Configuration cf2 = resolve(cf1, finder2, "m1", "m3");
-        ClassLoader loader2 = new ClassLoader() { };
-        Layer layer2 = layer1.defineModules(cf2, mn -> loader2);
-        assertTrue(layer2.modules().size() == 2);
-
-        Module m1_v1 = layer1.findModule("m1").get();
-        Module m2 = layer1.findModule("m2").get();
-
-        Module m1_v2 = layer2.findModule("m1").get();
-        Module m3 = layer2.findModule("m3").get();
-
-        assertTrue(m3.canRead(m1_v1));
-        assertFalse(m3.canRead(m1_v2));
-
-        assertFalse(m3.isExported("p"));
-        assertTrue(m3.isExported("p", m1_v1));
-        assertFalse(m3.isExported("p", m1_v2));
-        assertFalse(m3.isExported("p", m2));
-    }
-
-
-    /**
-     * Test layers with a qualified export. The target module is not in any layer.
-     *
-     * - Configuration/layer1: m1 { }
-     * - Configuration/layer2: m2 { exports p to m3; }
-     */
-    public void testQualifiedExports7() {
-        // create layer1 with m1
-        ModuleDescriptor descriptor1 = newBuilder("m1").build();
-        ModuleFinder finder1 = ModuleUtils.finderOf(descriptor1);
-        Configuration cf1 = resolve(finder1, "m1");
-        ClassLoader cl1 = new ClassLoader() { };
-        Layer layer1 = Layer.empty().defineModules(cf1, mn -> cl1);
-        assertTrue(layer1.modules().size() == 1);
-
-        // create layer2 with m2
-        ModuleDescriptor descriptor2 = newBuilder("m2")
-                .exports("p", Set.of("m3"))
-                .build();
-        ModuleFinder finder2 = ModuleUtils.finderOf(descriptor2);
-        Configuration cf2 = resolve(cf1, finder2, "m2");
-        ClassLoader cl2 = new ClassLoader() { };
-        Layer layer2 = layer1.defineModules(cf2, mn -> cl2);
-        assertTrue(layer2.modules().size() == 1);
-
-        Module m1 = layer1.findModule("m1").get();
-        Module m2 = layer2.findModule("m2").get();
-
-        // check m2 does not export p to anyone
-        assertFalse(m2.isExported("p"));
-        assertFalse(m2.isExported("p", m1));
-    }
-
-    /**
-     * Attempt to use Layer defineModules to create a layer with a module
-     * defined to a class loader that already has a module of the same name
-     * defined to the class loader.
-     */
-    @Test(expectedExceptions = { LayerInstantiationException.class })
-    public void testModuleAlreadyDefinedToLoader() {
-
-        ModuleDescriptor md = newBuilder("m")
-                .requires("java.base")
-                .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(md);
-
-        Configuration parent = Layer.boot().configuration();
-
-        Configuration cf = parent.resolve(finder, ModuleFinder.of(), Set.of("m"));
-
-        ClassLoader loader = new ClassLoader() { };
-
-        Layer.boot().defineModules(cf, mn -> loader);
-
-        // should throw LayerInstantiationException as m1 already defined to loader
-        Layer.boot().defineModules(cf, mn -> loader);
-
-    }
-
-
-    /**
-     * Attempt to use Layer defineModules to create a Layer with a module
-     * containing package {@code p} where the class loader already has a module
-     * defined to it containing package {@code p}.
-     */
-    @Test(expectedExceptions = { LayerInstantiationException.class })
-    public void testPackageAlreadyInNamedModule() {
-
-        ModuleDescriptor md1 = newBuilder("m1")
-                .packages(Set.of("p"))
-                .requires("java.base")
-                .build();
-
-        ModuleDescriptor md2 = newBuilder("m2")
-                .packages(Set.of("p"))
-                .requires("java.base")
-                .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(md1, md2);
-
-        ClassLoader loader = new ClassLoader() { };
-
-        // define m1 containing package p to class loader
-
-        Configuration parent = Layer.boot().configuration();
-
-        Configuration cf1 = parent.resolve(finder, ModuleFinder.of(), Set.of("m1"));
-
-        Layer layer1 = Layer.boot().defineModules(cf1, mn -> loader);
-
-        // attempt to define m2 containing package p to class loader
-
-        Configuration cf2 = parent.resolve(finder, ModuleFinder.of(), Set.of("m2"));
-
-        // should throw exception because p already in m1
-        Layer layer2 = Layer.boot().defineModules(cf2, mn -> loader);
-
-    }
-
-
-    /**
-     * Attempt to use Layer defineModules to create a Layer with a module
-     * containing a package in which a type is already loaded by the class
-     * loader.
-     */
-    @Test(expectedExceptions = { LayerInstantiationException.class })
-    public void testPackageAlreadyInUnnamedModule() throws Exception {
-
-        Class<?> c = layertest.Test.class;
-        assertFalse(c.getModule().isNamed());  // in unnamed module
-
-        ModuleDescriptor md = newBuilder("m")
-                .packages(Set.of(c.getPackageName()))
-                .requires("java.base")
-                .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(md);
-
-        Configuration parent = Layer.boot().configuration();
-        Configuration cf = parent.resolve(finder, ModuleFinder.of(), Set.of("m"));
-
-        Layer.boot().defineModules(cf, mn -> c.getClassLoader());
-    }
-
-
-    /**
-     * Attempt to create a Layer with a module named "java.base".
-     */
-    public void testLayerWithJavaBase() {
-        ModuleDescriptor descriptor = newBuilder("java.base")
-                .exports("java.lang")
-                .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(descriptor);
-
-        Configuration cf = Layer.boot()
-            .configuration()
-            .resolve(finder, ModuleFinder.of(), Set.of("java.base"));
-        assertTrue(cf.modules().size() == 1);
-
-        ClassLoader scl = ClassLoader.getSystemClassLoader();
-
-        try {
-            Layer.boot().defineModules(cf, mn -> new ClassLoader() { });
-            assertTrue(false);
-        } catch (LayerInstantiationException e) { }
-
-        try {
-            Layer.boot().defineModulesWithOneLoader(cf, scl);
-            assertTrue(false);
-        } catch (LayerInstantiationException e) { }
-
-        try {
-            Layer.boot().defineModulesWithManyLoaders(cf, scl);
-            assertTrue(false);
-        } catch (LayerInstantiationException e) { }
-    }
-
-
-    @DataProvider(name = "javaPackages")
-    public Object[][] javaPackages() {
-        return new Object[][] { { "m1", "java" }, { "m2", "java.x" } };
-    }
-
-    /**
-     * Attempt to create a Layer with a module containing a "java" package.
-     * This should only be allowed when the module is defined to the platform
-     * class loader.
-     */
-    @Test(dataProvider = "javaPackages")
-    public void testLayerWithJavaPackage(String mn, String pn) {
-        ModuleDescriptor descriptor = newBuilder(mn).packages(Set.of(pn)).build();
-        ModuleFinder finder = ModuleUtils.finderOf(descriptor);
-
-        Configuration cf = Layer.boot()
-                .configuration()
-                .resolve(finder, ModuleFinder.of(), Set.of(mn));
-        assertTrue(cf.modules().size() == 1);
-
-        ClassLoader pcl = ClassLoader.getPlatformClassLoader();
-        ClassLoader scl = ClassLoader.getSystemClassLoader();
-
-        try {
-            Layer.boot().defineModules(cf, _mn -> new ClassLoader() { });
-            assertTrue(false);
-        } catch (LayerInstantiationException e) { }
-
-        try {
-            Layer.boot().defineModulesWithOneLoader(cf, scl);
-            assertTrue(false);
-        } catch (LayerInstantiationException e) { }
-
-        try {
-            Layer.boot().defineModulesWithManyLoaders(cf, scl);
-            assertTrue(false);
-        } catch (LayerInstantiationException e) { }
-
-        // create layer with module defined to platform class loader
-        Layer layer = Layer.boot().defineModules(cf, _mn -> pcl);
-        Optional<Module> om = layer.findModule(mn);
-        assertTrue(om.isPresent());
-        Module foo = om.get();
-        assertTrue(foo.getClassLoader() == pcl);
-        assertTrue(foo.getPackages().length == 1);
-        assertTrue(foo.getPackages()[0].equals(pn));
-    }
-
-
-    /**
-     * Attempt to create a Layer with a module defined to the boot loader
-     */
-    @Test(expectedExceptions = { LayerInstantiationException.class })
-    public void testLayerWithBootLoader() {
-        ModuleDescriptor descriptor = newBuilder("m1")
-                .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(descriptor);
-
-        Configuration cf = Layer.boot()
-            .configuration()
-            .resolve(finder, ModuleFinder.of(), Set.of("m1"));
-        assertTrue(cf.modules().size() == 1);
-
-        Layer.boot().defineModules(cf, mn -> null );
-    }
-
-
-    /**
-     * Parent of configuration != configuration of parent Layer
-     */
-    @Test(expectedExceptions = { IllegalArgumentException.class })
-    public void testIncorrectParent1() {
-
-        ModuleDescriptor descriptor1 = newBuilder("m1")
-                .requires("java.base")
-                .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(descriptor1);
-
-        Configuration parent = Layer.boot().configuration();
-        Configuration cf = parent.resolve(finder, ModuleFinder.of(), Set.of("m1"));
-
-        ClassLoader loader = new ClassLoader() { };
-        Layer.empty().defineModules(cf, mn -> loader);
-    }
-
-
-    /**
-     * Parent of configuration != configuration of parent Layer
-     */
-    @Test(expectedExceptions = { IllegalArgumentException.class })
-    public void testIncorrectParent2() {
-
-        ModuleDescriptor descriptor1 = newBuilder("m1")
-                .build();
-
-        ModuleFinder finder = ModuleUtils.finderOf(descriptor1);
-
-        Configuration cf = resolve(finder, "m1");
-
-        ClassLoader loader = new ClassLoader() { };
-        Layer.boot().defineModules(cf, mn -> loader);
-    }
-
-
-    // null handling
-
-    @Test(expectedExceptions = { NullPointerException.class })
-    public void testCreateWithNull1() {
-        ClassLoader loader = new ClassLoader() { };
-        Layer.empty().defineModules(null, mn -> loader);
-    }
-
-    @Test(expectedExceptions = { NullPointerException.class })
-    public void testCreateWithNull2() {
-        Configuration cf = resolve(Layer.boot().configuration(), ModuleFinder.of());
-        Layer.boot().defineModules(cf, null);
-    }
-
-    @Test(expectedExceptions = { NullPointerException.class })
-    public void testCreateWithNull3() {
-        ClassLoader scl = ClassLoader.getSystemClassLoader();
-        Layer.empty().defineModulesWithOneLoader(null, scl);
-    }
-
-    @Test(expectedExceptions = { NullPointerException.class })
-    public void testCreateWithNull4() {
-        ClassLoader scl = ClassLoader.getSystemClassLoader();
-        Layer.empty().defineModulesWithManyLoaders(null, scl);
-    }
-
-    @Test(expectedExceptions = { NullPointerException.class })
-    public void testFindModuleWithNull() {
-        Layer.boot().findModule(null);
-    }
-
-    @Test(expectedExceptions = { NullPointerException.class })
-    public void testFindLoaderWithNull() {
-        Layer.boot().findLoader(null);
-    }
-
-
-    // immutable sets
-
-    @Test(expectedExceptions = { UnsupportedOperationException.class })
-    public void testImmutableSet() {
-        Module base = Object.class.getModule();
-        Layer.boot().modules().add(base);
-    }
-
-
-    /**
-     * Resolve the given modules, by name, and returns the resulting
-     * Configuration.
-     */
-    private static Configuration resolve(Configuration cf,
-                                         ModuleFinder finder,
-                                         String... roots) {
-        return cf.resolve(finder, ModuleFinder.of(), Set.of(roots));
-    }
-
-    private static Configuration resolve(ModuleFinder finder,
-                                         String... roots) {
-        return resolve(Configuration.empty(), finder, roots);
-    }
-}