util/Collections/EmptyNavigableSet.java

/*
 * Copyright (c) 2011, 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
 * @bug 4533691 7129185
 * @summary Unit test for Collections.emptyNavigableSet
 * @run testng EmptyNavigableSet
 */
import java.math.BigInteger;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.NavigableSet;
import java.util.SortedSet;
import java.util.TreeSet;

import org.testng.Assert;
import org.testng.Assert.ThrowingRunnable;
import org.testng.annotations.Test;
import org.testng.annotations.DataProvider;

import static org.testng.Assert.assertFalse;
import static org.testng.Assert.assertSame;
import static org.testng.Assert.assertTrue;

public class EmptyNavigableSet {

    public static <T> void assertInstance(T actual, Class<? extends T> expected) {
        assertInstance(actual, expected, null);
    }

    public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
        assertTrue(expected.isInstance(actual), ((null != message) ? message : "")
            + " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");
    }

    public static <T extends Throwable> void assertEmptyNavigableSet(Object obj) {
        assertInstance(obj, NavigableSet.class);
        assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0));
    }

    public static <T extends Throwable> void assertEmptyNavigableSet(Object obj, String message) {
        assertInstance(obj, NavigableSet.class, message);
        assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0),
            ((null != message) ? message : "") + " Not empty. ");
    }

    private <T extends Throwable> void assertThrows(Class<T> throwableClass,
                                                    ThrowingRunnable runnable,
                                                    String message) {
        try {
            Assert.assertThrows(throwableClass, runnable);
        } catch (AssertionError e) {
            throw new AssertionError(String.format("%s%n%s",
                    ((null != message) ? message : ""), e.getMessage()), e);
        }
    }

    private void assertThrowsCCE(ThrowingRunnable r, String s) {
        assertThrows(ClassCastException.class, r, s);
    }

    private void assertThrowsNPE(ThrowingRunnable r, String s) {
        assertThrows(NullPointerException.class, r, s);
    }

    private void assertThrowsIAE(ThrowingRunnable r, String s) {
        assertThrows(IllegalArgumentException.class, r, s);
    }

    private void assertThrowsNSEE(ThrowingRunnable r, String s) {
        assertThrows(NoSuchElementException.class, r, s);
    }

    public static final boolean isDescending(SortedSet<?> set) {
        if (null == set.comparator()) {
            // natural order
            return false;
        }

        if (Collections.reverseOrder() == set.comparator()) {
            // reverse natural order.
            return true;
        }

        if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {
            // it's a Collections.reverseOrder(Comparator).
            return true;
        }

        throw new IllegalStateException("can't determine ordering for " + set);
    }

    /**
     * Tests that the comparator is {@code null}.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testComparatorIsNull(String description, NavigableSet<?> navigableSet) {
        Comparator comparator = navigableSet.comparator();

        assertTrue(comparator == null || comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");
    }

    /**
     * Tests that contains requires Comparable
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testContainsRequiresComparable(String description, NavigableSet<?> navigableSet) {
        assertThrowsCCE(
            () -> navigableSet.contains(new Object()),
            description + ": Comparable should be required");
    }

    /**
     * Tests that the contains method returns {@code false}.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testContains(String description, NavigableSet<?> navigableSet) {
        assertFalse(navigableSet.contains(new Integer(1)),
            description + ": Should not contain any elements.");
    }

    /**
     * Tests that the containsAll method returns {@code false}.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testContainsAll(String description, NavigableSet<?> navigableSet) {
        TreeSet treeSet = new TreeSet();
        treeSet.add("1");
        treeSet.add("2");
        treeSet.add("3");

        assertFalse(navigableSet.containsAll(treeSet), "Should not contain any elements.");
    }

    /**
     * Tests that the iterator is empty.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
        Iterator emptyIterator = navigableSet.iterator();

        assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
            "The iterator is not empty.");
    }

    /**
     * Tests that the set is empty.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testIsEmpty(String description, NavigableSet<?> navigableSet) {
        assertTrue(navigableSet.isEmpty(), "The set is not empty.");
    }

    /**
     * Tests that the first() method throws NoSuchElementException
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testFirst(String description, NavigableSet<?> navigableSet) {
        assertThrowsNSEE(navigableSet::first, description);
    }

    /**
     * Tests the headSet() method.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testHeadSet(String description, NavigableSet navigableSet) {
        assertThrowsNPE(
            () -> { NavigableSet ns = navigableSet.headSet(null, false); },
            description + ": Must throw NullPointerException for null element");

        assertThrowsCCE(
            () -> { NavigableSet ns = navigableSet.headSet(new Object(), true); },
            description + ": Must throw ClassCastException for non-Comparable element");

        NavigableSet ns = navigableSet.headSet("1", false);

        assertEmptyNavigableSet(ns, description + ": Returned value is not empty navigable set.");
    }

    /**
     * Tests that the last() method throws NoSuchElementException
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testLast(String description, NavigableSet<?> navigableSet) {
        assertThrowsNSEE(navigableSet::last, description);
    }

    /**
     * Tests that the size is 0.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testSizeIsZero(String description, NavigableSet<?> navigableSet) {
        assertTrue(0 == navigableSet.size(), "The size of the set is not 0.");
    }

    /**
     * Tests the subSet() method.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testSubSet(String description, NavigableSet navigableSet) {
        assertThrowsNPE(
            () -> {
                SortedSet ss = navigableSet.subSet(null, BigInteger.TEN);
            },
            description + ": Must throw NullPointerException for null element");

        assertThrowsNPE(
            () -> {
                SortedSet ss = navigableSet.subSet(BigInteger.ZERO, null);
            },
            description + ": Must throw NullPointerException for null element");

        assertThrowsNPE(
            () -> {
                SortedSet ss = navigableSet.subSet(null, null);
            },
            description + ": Must throw NullPointerException for null element");

        Object obj1 = new Object();
        Object obj2 = new Object();

        assertThrowsCCE(
            () -> {
                SortedSet ss = navigableSet.subSet(obj1, BigInteger.TEN);
            },
            description + ": Must throw ClassCastException for parameter which is not Comparable.");

        assertThrowsCCE(
            () -> {
                SortedSet ss = navigableSet.subSet(BigInteger.ZERO, obj2);
            },
            description + ": Must throw ClassCastException for parameter which is not Comparable.");

        assertThrowsCCE(
            () -> {
                SortedSet ss = navigableSet.subSet(obj1, obj2);
            },
            description + ": Must throw ClassCastException for parameter which is not Comparable.");

        // minimal range
        navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, false);
        navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, true);
        navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, false);
        navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, true);

        Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

            assertThrowsIAE(
                () -> navigableSet.subSet(last, true, first, false),
                description
                + ": Must throw IllegalArgumentException when fromElement is not less than toElement.");

        navigableSet.subSet(first, true, last, false);
    }

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testSubSetRanges(String description, NavigableSet navigableSet) {
        Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
        Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;

        NavigableSet subSet = navigableSet.subSet(first, true, last, true);

        // same subset
        subSet.subSet(first, true, last, true);

        // slightly smaller
        NavigableSet ns = subSet.subSet(first, false, last, false);
        // slight expansion
        assertThrowsIAE(
            () -> ns.subSet(first, true, last, true),
            description + ": Expansion should not be allowed");

        // much smaller
        subSet.subSet(first, false, BigInteger.ONE, false);
    }

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testheadSetRanges(String description, NavigableSet navigableSet) {
        NavigableSet subSet = navigableSet.headSet(BigInteger.ONE, true);

        // same subset
        subSet.headSet(BigInteger.ONE, true);

        // slightly smaller
        NavigableSet ns = subSet.headSet(BigInteger.ONE, false);

        // slight expansion
        assertThrowsIAE(
            () -> ns.headSet(BigInteger.ONE, true),
            description + ": Expansion should not be allowed");

        // much smaller
        subSet.headSet(isDescending(subSet) ? BigInteger.TEN : BigInteger.ZERO, true);
    }

    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testTailSetRanges(String description, NavigableSet navigableSet) {
        NavigableSet subSet = navigableSet.tailSet(BigInteger.ONE, true);

        // same subset
        subSet.tailSet(BigInteger.ONE, true);

        // slightly smaller
        NavigableSet ns = subSet.tailSet(BigInteger.ONE, false);

        // slight expansion
        assertThrowsIAE(
            () -> ns.tailSet(BigInteger.ONE, true),
            description + ": Expansion should not be allowed");

        // much smaller
        subSet.tailSet(isDescending(subSet) ? BigInteger.ZERO : BigInteger.TEN, false);
    }

    /**
     * Tests the tailSet() method.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testTailSet(String description, NavigableSet navigableSet) {
        assertThrowsNPE(
            () -> navigableSet.tailSet(null),
            description + ": Must throw NullPointerException for null element");

        assertThrowsCCE(
            () -> navigableSet.tailSet(new Object()),
            description);

        NavigableSet ss = navigableSet.tailSet("1", true);

        assertEmptyNavigableSet(ss, description + ": Returned value is not empty navigable set.");
    }

    /**
     * Tests that the array has a size of 0.
     */
    @Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
    public void testToArray(String description, NavigableSet<?> navigableSet) {
        Object[] emptyNavigableSetArray = navigableSet.toArray();

        assertTrue(emptyNavigableSetArray.length == 0, "Returned non-empty Array.");

        emptyNavigableSetArray = new Object[20];

        Object[] result = navigableSet.toArray(emptyNavigableSetArray);

        assertSame(emptyNavigableSetArray, result);

        assertTrue(result[0] == null);
    }

    @DataProvider(name = "NavigableSet<?>", parallel = true)
    public static Iterator<Object[]> navigableSetsProvider() {
        return makeNavigableSets().iterator();
    }

    public static Collection<Object[]> makeNavigableSets() {
        return Arrays.asList(
            new Object[]{"UnmodifiableNavigableSet(TreeSet)", Collections.unmodifiableNavigableSet(new TreeSet())},
            new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet())},
            new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet().descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet().descendingSet())},
            new Object[]{"emptyNavigableSet()", Collections.emptyNavigableSet()},
            new Object[]{"emptyNavigableSet().descendingSet()", Collections.emptyNavigableSet().descendingSet()},
            new Object[]{"emptyNavigableSet().descendingSet().descendingSet()", Collections.emptyNavigableSet().descendingSet().descendingSet()}
        );
    }
}
Revision:	1.10
Committed:	Sun Jan 7 23:48:13 2018 UTC (6 years, 4 months ago) by jsr166
Branch:	MAIN
Changes since 1.9:	+1 -1 lines
Log Message:	typo
#	User	Rev	Content
1	jsr166	1.1	/*
2	jsr166	1.6	* Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
3	jsr166	1.1	* 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			/*
25			* @test
26			* @bug 4533691 7129185
27			* @summary Unit test for Collections.emptyNavigableSet
28			* @run testng EmptyNavigableSet
29			*/
30			import java.math.BigInteger;
31			import java.util.Arrays;
32			import java.util.Collection;
33			import java.util.Collections;
34			import java.util.Comparator;
35			import java.util.Iterator;
36			import java.util.NoSuchElementException;
37			import java.util.NavigableSet;
38			import java.util.SortedSet;
39			import java.util.TreeSet;
40	jsr166	1.6
41			import org.testng.Assert;
42			import org.testng.Assert.ThrowingRunnable;
43	jsr166	1.1	import org.testng.annotations.Test;
44			import org.testng.annotations.DataProvider;
45
46			import static org.testng.Assert.assertFalse;
47			import static org.testng.Assert.assertSame;
48	jsr166	1.4	import static org.testng.Assert.assertTrue;
49	jsr166	1.1
50			public class EmptyNavigableSet {
51
52			public static <T> void assertInstance(T actual, Class<? extends T> expected) {
53	jsr166	1.7	assertInstance(actual, expected, null);
54	jsr166	1.1	}
55
56			public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
57			assertTrue(expected.isInstance(actual), ((null != message) ? message : "")
58			+ " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");
59			}
60
61			public static <T extends Throwable> void assertEmptyNavigableSet(Object obj) {
62			assertInstance(obj, NavigableSet.class);
63			assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0));
64			}
65
66			public static <T extends Throwable> void assertEmptyNavigableSet(Object obj, String message) {
67			assertInstance(obj, NavigableSet.class, message);
68			assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0),
69			((null != message) ? message : "") + " Not empty. ");
70			}
71
72	jsr166	1.6	private <T extends Throwable> void assertThrows(Class<T> throwableClass,
73			ThrowingRunnable runnable,
74			String message) {
75			try {
76			Assert.assertThrows(throwableClass, runnable);
77			} catch (AssertionError e) {
78			throw new AssertionError(String.format("%s%n%s",
79			((null != message) ? message : ""), e.getMessage()), e);
80			}
81			}
82	jsr166	1.1
83	jsr166	1.6	private void assertThrowsCCE(ThrowingRunnable r, String s) {
84			assertThrows(ClassCastException.class, r, s);
85	jsr166	1.1	}
86
87	jsr166	1.6	private void assertThrowsNPE(ThrowingRunnable r, String s) {
88			assertThrows(NullPointerException.class, r, s);
89	jsr166	1.1	}
90
91	jsr166	1.6	private void assertThrowsIAE(ThrowingRunnable r, String s) {
92			assertThrows(IllegalArgumentException.class, r, s);
93			}
94	jsr166	1.1
95	jsr166	1.6	private void assertThrowsNSEE(ThrowingRunnable r, String s) {
96			assertThrows(NoSuchElementException.class, r, s);
97	jsr166	1.1	}
98
99			public static final boolean isDescending(SortedSet<?> set) {
100			if (null == set.comparator()) {
101			// natural order
102			return false;
103			}
104
105			if (Collections.reverseOrder() == set.comparator()) {
106			// reverse natural order.
107			return true;
108			}
109
110			if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {
111			// it's a Collections.reverseOrder(Comparator).
112			return true;
113			}
114
115			throw new IllegalStateException("can't determine ordering for " + set);
116			}
117
118			/**
119			* Tests that the comparator is {@code null}.
120			*/
121			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
122			public void testComparatorIsNull(String description, NavigableSet<?> navigableSet) {
123			Comparator comparator = navigableSet.comparator();
124
125			assertTrue(comparator == null \|\| comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");
126			}
127
128			/**
129			* Tests that contains requires Comparable
130			*/
131			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
132			public void testContainsRequiresComparable(String description, NavigableSet<?> navigableSet) {
133	jsr166	1.9	assertThrowsCCE(
134			() -> navigableSet.contains(new Object()),
135	jsr166	1.10	description + ": Comparable should be required");
136	jsr166	1.1	}
137
138			/**
139			* Tests that the contains method returns {@code false}.
140			*/
141			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
142			public void testContains(String description, NavigableSet<?> navigableSet) {
143			assertFalse(navigableSet.contains(new Integer(1)),
144			description + ": Should not contain any elements.");
145			}
146
147			/**
148			* Tests that the containsAll method returns {@code false}.
149			*/
150			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
151			public void testContainsAll(String description, NavigableSet<?> navigableSet) {
152			TreeSet treeSet = new TreeSet();
153			treeSet.add("1");
154			treeSet.add("2");
155			treeSet.add("3");
156
157			assertFalse(navigableSet.containsAll(treeSet), "Should not contain any elements.");
158			}
159
160			/**
161			* Tests that the iterator is empty.
162			*/
163			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
164			public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
165			Iterator emptyIterator = navigableSet.iterator();
166
167			assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
168			"The iterator is not empty.");
169			}
170
171			/**
172			* Tests that the set is empty.
173			*/
174			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
175			public void testIsEmpty(String description, NavigableSet<?> navigableSet) {
176			assertTrue(navigableSet.isEmpty(), "The set is not empty.");
177			}
178
179			/**
180			* Tests that the first() method throws NoSuchElementException
181			*/
182			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
183			public void testFirst(String description, NavigableSet<?> navigableSet) {
184	jsr166	1.8	assertThrowsNSEE(navigableSet::first, description);
185	jsr166	1.1	}
186
187			/**
188			* Tests the headSet() method.
189			*/
190			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
191			public void testHeadSet(String description, NavigableSet navigableSet) {
192	jsr166	1.6	assertThrowsNPE(
193	jsr166	1.1	() -> { NavigableSet ns = navigableSet.headSet(null, false); },
194			description + ": Must throw NullPointerException for null element");
195
196	jsr166	1.6	assertThrowsCCE(
197	jsr166	1.1	() -> { NavigableSet ns = navigableSet.headSet(new Object(), true); },
198			description + ": Must throw ClassCastException for non-Comparable element");
199
200			NavigableSet ns = navigableSet.headSet("1", false);
201
202			assertEmptyNavigableSet(ns, description + ": Returned value is not empty navigable set.");
203			}
204
205			/**
206			* Tests that the last() method throws NoSuchElementException
207			*/
208			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
209			public void testLast(String description, NavigableSet<?> navigableSet) {
210	jsr166	1.8	assertThrowsNSEE(navigableSet::last, description);
211	jsr166	1.1	}
212
213			/**
214			* Tests that the size is 0.
215			*/
216			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
217			public void testSizeIsZero(String description, NavigableSet<?> navigableSet) {
218			assertTrue(0 == navigableSet.size(), "The size of the set is not 0.");
219			}
220
221			/**
222			* Tests the subSet() method.
223			*/
224			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
225			public void testSubSet(String description, NavigableSet navigableSet) {
226	jsr166	1.6	assertThrowsNPE(
227	jsr166	1.1	() -> {
228			SortedSet ss = navigableSet.subSet(null, BigInteger.TEN);
229			},
230			description + ": Must throw NullPointerException for null element");
231
232	jsr166	1.6	assertThrowsNPE(
233	jsr166	1.1	() -> {
234			SortedSet ss = navigableSet.subSet(BigInteger.ZERO, null);
235			},
236			description + ": Must throw NullPointerException for null element");
237
238	jsr166	1.6	assertThrowsNPE(
239	jsr166	1.1	() -> {
240			SortedSet ss = navigableSet.subSet(null, null);
241			},
242			description + ": Must throw NullPointerException for null element");
243
244			Object obj1 = new Object();
245			Object obj2 = new Object();
246
247	jsr166	1.6	assertThrowsCCE(
248	jsr166	1.1	() -> {
249			SortedSet ss = navigableSet.subSet(obj1, BigInteger.TEN);
250			},
251	jsr166	1.6	description + ": Must throw ClassCastException for parameter which is not Comparable.");
252	jsr166	1.1
253	jsr166	1.6	assertThrowsCCE(
254	jsr166	1.1	() -> {
255			SortedSet ss = navigableSet.subSet(BigInteger.ZERO, obj2);
256			},
257	jsr166	1.6	description + ": Must throw ClassCastException for parameter which is not Comparable.");
258	jsr166	1.1
259	jsr166	1.6	assertThrowsCCE(
260	jsr166	1.1	() -> {
261			SortedSet ss = navigableSet.subSet(obj1, obj2);
262			},
263	jsr166	1.6	description + ": Must throw ClassCastException for parameter which is not Comparable.");
264	jsr166	1.1
265			// minimal range
266			navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, false);
267			navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, true);
268			navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, false);
269			navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, true);
270
271			Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
272			Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
273
274	jsr166	1.6	assertThrowsIAE(
275	jsr166	1.9	() -> navigableSet.subSet(last, true, first, false),
276	jsr166	1.6	description
277	jsr166	1.3	+ ": Must throw IllegalArgumentException when fromElement is not less than toElement.");
278	jsr166	1.1
279			navigableSet.subSet(first, true, last, false);
280			}
281
282			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
283			public void testSubSetRanges(String description, NavigableSet navigableSet) {
284			Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
285			Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
286
287			NavigableSet subSet = navigableSet.subSet(first, true, last, true);
288
289			// same subset
290			subSet.subSet(first, true, last, true);
291
292			// slightly smaller
293			NavigableSet ns = subSet.subSet(first, false, last, false);
294	jsr166	1.2	// slight expansion
295	jsr166	1.9	assertThrowsIAE(
296			() -> ns.subSet(first, true, last, true),
297	jsr166	1.1	description + ": Expansion should not be allowed");
298
299			// much smaller
300			subSet.subSet(first, false, BigInteger.ONE, false);
301			}
302
303			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
304			public void testheadSetRanges(String description, NavigableSet navigableSet) {
305			NavigableSet subSet = navigableSet.headSet(BigInteger.ONE, true);
306
307			// same subset
308			subSet.headSet(BigInteger.ONE, true);
309
310			// slightly smaller
311			NavigableSet ns = subSet.headSet(BigInteger.ONE, false);
312
313	jsr166	1.2	// slight expansion
314	jsr166	1.9	assertThrowsIAE(
315			() -> ns.headSet(BigInteger.ONE, true),
316	jsr166	1.1	description + ": Expansion should not be allowed");
317
318			// much smaller
319			subSet.headSet(isDescending(subSet) ? BigInteger.TEN : BigInteger.ZERO, true);
320			}
321
322			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
323			public void testTailSetRanges(String description, NavigableSet navigableSet) {
324			NavigableSet subSet = navigableSet.tailSet(BigInteger.ONE, true);
325
326			// same subset
327			subSet.tailSet(BigInteger.ONE, true);
328
329			// slightly smaller
330			NavigableSet ns = subSet.tailSet(BigInteger.ONE, false);
331
332	jsr166	1.2	// slight expansion
333	jsr166	1.9	assertThrowsIAE(
334			() -> ns.tailSet(BigInteger.ONE, true),
335	jsr166	1.1	description + ": Expansion should not be allowed");
336
337			// much smaller
338			subSet.tailSet(isDescending(subSet) ? BigInteger.ZERO : BigInteger.TEN, false);
339			}
340
341			/**
342			* Tests the tailSet() method.
343			*/
344			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
345			public void testTailSet(String description, NavigableSet navigableSet) {
346	jsr166	1.9	assertThrowsNPE(
347			() -> navigableSet.tailSet(null),
348	jsr166	1.1	description + ": Must throw NullPointerException for null element");
349
350	jsr166	1.9	assertThrowsCCE(
351			() -> navigableSet.tailSet(new Object()),
352			description);
353	jsr166	1.1
354			NavigableSet ss = navigableSet.tailSet("1", true);
355
356			assertEmptyNavigableSet(ss, description + ": Returned value is not empty navigable set.");
357			}
358
359			/**
360			* Tests that the array has a size of 0.
361			*/
362			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
363			public void testToArray(String description, NavigableSet<?> navigableSet) {
364			Object[] emptyNavigableSetArray = navigableSet.toArray();
365
366			assertTrue(emptyNavigableSetArray.length == 0, "Returned non-empty Array.");
367
368			emptyNavigableSetArray = new Object[20];
369
370			Object[] result = navigableSet.toArray(emptyNavigableSetArray);
371
372			assertSame(emptyNavigableSetArray, result);
373
374			assertTrue(result[0] == null);
375			}
376
377			@DataProvider(name = "NavigableSet<?>", parallel = true)
378			public static Iterator<Object[]> navigableSetsProvider() {
379			return makeNavigableSets().iterator();
380			}
381
382			public static Collection<Object[]> makeNavigableSets() {
383			return Arrays.asList(
384			new Object[]{"UnmodifiableNavigableSet(TreeSet)", Collections.unmodifiableNavigableSet(new TreeSet())},
385			new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet())},
386			new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet().descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet().descendingSet())},
387			new Object[]{"emptyNavigableSet()", Collections.emptyNavigableSet()},
388			new Object[]{"emptyNavigableSet().descendingSet()", Collections.emptyNavigableSet().descendingSet()},
389			new Object[]{"emptyNavigableSet().descendingSet().descendingSet()", Collections.emptyNavigableSet().descendingSet().descendingSet()}
390			);
391			}
392			}