util/Collections/EmptyNavigableSet.java

/*
 * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * 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.annotations.Test;
import org.testng.annotations.DataProvider;

import static org.testng.Assert.fail;
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(expected.isInstance(actual), 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. ");
    }

    public interface Thrower<T extends Throwable> {

        public void run() throws T;
    }

    public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable) {
        assertThrows(thrower, throwable, null);
    }

    public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable, String message) {
        Throwable result;
        try {
            thrower.run();
            fail(((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
            return;
        } catch (Throwable caught) {
            result = caught;
        }

        assertInstance(result, throwable, ((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
    }

    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) {
        assertThrows(() -> {
            navigableSet.contains(new Object());
        },
            ClassCastException.class,
            description + ": Compareable 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) {
        assertThrows(() -> {
            navigableSet.first();
        }, NoSuchElementException.class, description);
    }

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

        assertThrows(
            () -> { NavigableSet ns = navigableSet.headSet(new Object(), true); },
            ClassCastException.class,
            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) {
        assertThrows(() -> {
            navigableSet.last();
        }, NoSuchElementException.class, 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) {
        assertThrows(
            () -> {
                SortedSet ss = navigableSet.subSet(null, BigInteger.TEN);
            },
            NullPointerException.class,
            description + ": Must throw NullPointerException for null element");

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

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

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

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

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

        assertThrows(
            () -> {
                SortedSet ss = navigableSet.subSet(obj1, obj2);
            },
            ClassCastException.class, 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;

            assertThrows(
                () -> {
                    navigableSet.subSet(last, true, first, false);
                },
                IllegalArgumentException.class, 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
        assertThrows(() -> {
            ns.subSet(first, true, last, true);
        },
            IllegalArgumentException.class,
            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
        assertThrows(() -> {
            ns.headSet(BigInteger.ONE, true);
        },
            IllegalArgumentException.class,
            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
        assertThrows(() -> {
            ns.tailSet(BigInteger.ONE, true);
        },
            IllegalArgumentException.class,
            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) {
        assertThrows(() -> {
            navigableSet.tailSet(null);
        },
            NullPointerException.class,
            description + ": Must throw NullPointerException for null element");

        assertThrows(() -> {
            navigableSet.tailSet(new Object());
        }, ClassCastException.class);

        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:	1.4
Committed:	Sat Sep 17 20:38:49 2016 UTC (7 years, 7 months ago) by jsr166
Branch:	MAIN
Changes since 1.3:	+1 -2 lines
Log Message:	tidy imports
#	User	Rev	Content
1	jsr166	1.1	/*
2			* Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
3			* 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			import org.testng.annotations.Test;
41			import org.testng.annotations.DataProvider;
42
43			import static org.testng.Assert.fail;
44			import static org.testng.Assert.assertFalse;
45			import static org.testng.Assert.assertSame;
46	jsr166	1.4	import static org.testng.Assert.assertTrue;
47	jsr166	1.1
48			public class EmptyNavigableSet {
49
50			public static <T> void assertInstance(T actual, Class<? extends T> expected) {
51			assertInstance(expected.isInstance(actual), null);
52			}
53
54			public static <T> void assertInstance(T actual, Class<? extends T> expected, String message) {
55			assertTrue(expected.isInstance(actual), ((null != message) ? message : "")
56			+ " " + (actual == null ? "<null>" : actual.getClass().getSimpleName()) + " != " + expected.getSimpleName() + ". ");
57			}
58
59			public static <T extends Throwable> void assertEmptyNavigableSet(Object obj) {
60			assertInstance(obj, NavigableSet.class);
61			assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0));
62			}
63
64			public static <T extends Throwable> void assertEmptyNavigableSet(Object obj, String message) {
65			assertInstance(obj, NavigableSet.class, message);
66			assertTrue(((NavigableSet)obj).isEmpty() && (((NavigableSet)obj).size() == 0),
67			((null != message) ? message : "") + " Not empty. ");
68			}
69
70			public interface Thrower<T extends Throwable> {
71
72			public void run() throws T;
73			}
74
75			public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable) {
76			assertThrows(thrower, throwable, null);
77			}
78
79			public static <T extends Throwable> void assertThrows(Thrower<T> thrower, Class<T> throwable, String message) {
80			Throwable result;
81			try {
82			thrower.run();
83			fail(((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
84			return;
85			} catch (Throwable caught) {
86			result = caught;
87			}
88
89			assertInstance(result, throwable, ((null != message) ? message : "") + "Failed to throw " + throwable.getCanonicalName() + ". ");
90			}
91
92			public static final boolean isDescending(SortedSet<?> set) {
93			if (null == set.comparator()) {
94			// natural order
95			return false;
96			}
97
98			if (Collections.reverseOrder() == set.comparator()) {
99			// reverse natural order.
100			return true;
101			}
102
103			if (set.comparator().equals(Collections.reverseOrder(Collections.reverseOrder(set.comparator())))) {
104			// it's a Collections.reverseOrder(Comparator).
105			return true;
106			}
107
108			throw new IllegalStateException("can't determine ordering for " + set);
109			}
110
111			/**
112			* Tests that the comparator is {@code null}.
113			*/
114			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
115			public void testComparatorIsNull(String description, NavigableSet<?> navigableSet) {
116			Comparator comparator = navigableSet.comparator();
117
118			assertTrue(comparator == null \|\| comparator == Collections.reverseOrder(), description + ": Comparator (" + comparator + ") is not null.");
119			}
120
121			/**
122			* Tests that contains requires Comparable
123			*/
124			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
125			public void testContainsRequiresComparable(String description, NavigableSet<?> navigableSet) {
126			assertThrows(() -> {
127			navigableSet.contains(new Object());
128			},
129			ClassCastException.class,
130			description + ": Compareable should be required");
131			}
132
133			/**
134			* Tests that the contains method returns {@code false}.
135			*/
136			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
137			public void testContains(String description, NavigableSet<?> navigableSet) {
138			assertFalse(navigableSet.contains(new Integer(1)),
139			description + ": Should not contain any elements.");
140			}
141
142			/**
143			* Tests that the containsAll method returns {@code false}.
144			*/
145			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
146			public void testContainsAll(String description, NavigableSet<?> navigableSet) {
147			TreeSet treeSet = new TreeSet();
148			treeSet.add("1");
149			treeSet.add("2");
150			treeSet.add("3");
151
152			assertFalse(navigableSet.containsAll(treeSet), "Should not contain any elements.");
153			}
154
155			/**
156			* Tests that the iterator is empty.
157			*/
158			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
159			public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
160			Iterator emptyIterator = navigableSet.iterator();
161
162			assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
163			"The iterator is not empty.");
164			}
165
166			/**
167			* Tests that the set is empty.
168			*/
169			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
170			public void testIsEmpty(String description, NavigableSet<?> navigableSet) {
171			assertTrue(navigableSet.isEmpty(), "The set is not empty.");
172			}
173
174			/**
175			* Tests that the first() method throws NoSuchElementException
176			*/
177			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
178			public void testFirst(String description, NavigableSet<?> navigableSet) {
179			assertThrows(() -> {
180			navigableSet.first();
181			}, NoSuchElementException.class, description);
182			}
183
184			/**
185			* Tests the headSet() method.
186			*/
187			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
188			public void testHeadSet(String description, NavigableSet navigableSet) {
189			assertThrows(
190			() -> { NavigableSet ns = navigableSet.headSet(null, false); },
191			NullPointerException.class,
192			description + ": Must throw NullPointerException for null element");
193
194			assertThrows(
195			() -> { NavigableSet ns = navigableSet.headSet(new Object(), true); },
196			ClassCastException.class,
197			description + ": Must throw ClassCastException for non-Comparable element");
198
199			NavigableSet ns = navigableSet.headSet("1", false);
200
201			assertEmptyNavigableSet(ns, description + ": Returned value is not empty navigable set.");
202			}
203
204			/**
205			* Tests that the last() method throws NoSuchElementException
206			*/
207			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
208			public void testLast(String description, NavigableSet<?> navigableSet) {
209			assertThrows(() -> {
210			navigableSet.last();
211			}, NoSuchElementException.class, description);
212			}
213
214			/**
215			* Tests that the size is 0.
216			*/
217			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
218			public void testSizeIsZero(String description, NavigableSet<?> navigableSet) {
219			assertTrue(0 == navigableSet.size(), "The size of the set is not 0.");
220			}
221
222			/**
223			* Tests the subSet() method.
224			*/
225			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
226			public void testSubSet(String description, NavigableSet navigableSet) {
227			assertThrows(
228			() -> {
229			SortedSet ss = navigableSet.subSet(null, BigInteger.TEN);
230			},
231			NullPointerException.class,
232			description + ": Must throw NullPointerException for null element");
233
234			assertThrows(
235			() -> {
236			SortedSet ss = navigableSet.subSet(BigInteger.ZERO, null);
237			},
238			NullPointerException.class,
239			description + ": Must throw NullPointerException for null element");
240
241			assertThrows(
242			() -> {
243			SortedSet ss = navigableSet.subSet(null, null);
244			},
245			NullPointerException.class,
246			description + ": Must throw NullPointerException for null element");
247
248			Object obj1 = new Object();
249			Object obj2 = new Object();
250
251			assertThrows(
252			() -> {
253			SortedSet ss = navigableSet.subSet(obj1, BigInteger.TEN);
254			},
255			ClassCastException.class, description
256			+ ": Must throw ClassCastException for parameter which is not Comparable.");
257
258			assertThrows(
259			() -> {
260			SortedSet ss = navigableSet.subSet(BigInteger.ZERO, obj2);
261			},
262			ClassCastException.class, description
263			+ ": Must throw ClassCastException for parameter which is not Comparable.");
264
265			assertThrows(
266			() -> {
267			SortedSet ss = navigableSet.subSet(obj1, obj2);
268			},
269			ClassCastException.class, description
270			+ ": Must throw ClassCastException for parameter which is not Comparable.");
271
272			// minimal range
273			navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, false);
274			navigableSet.subSet(BigInteger.ZERO, false, BigInteger.ZERO, true);
275			navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, false);
276			navigableSet.subSet(BigInteger.ZERO, true, BigInteger.ZERO, true);
277
278			Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
279			Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
280
281			assertThrows(
282			() -> {
283			navigableSet.subSet(last, true, first, false);
284			},
285			IllegalArgumentException.class, description
286	jsr166	1.3	+ ": Must throw IllegalArgumentException when fromElement is not less than toElement.");
287	jsr166	1.1
288			navigableSet.subSet(first, true, last, false);
289			}
290
291			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
292			public void testSubSetRanges(String description, NavigableSet navigableSet) {
293			Object first = isDescending(navigableSet) ? BigInteger.TEN : BigInteger.ZERO;
294			Object last = (BigInteger.ZERO == first) ? BigInteger.TEN : BigInteger.ZERO;
295
296			NavigableSet subSet = navigableSet.subSet(first, true, last, true);
297
298			// same subset
299			subSet.subSet(first, true, last, true);
300
301			// slightly smaller
302			NavigableSet ns = subSet.subSet(first, false, last, false);
303	jsr166	1.2	// slight expansion
304	jsr166	1.1	assertThrows(() -> {
305			ns.subSet(first, true, last, true);
306			},
307			IllegalArgumentException.class,
308			description + ": Expansion should not be allowed");
309
310			// much smaller
311			subSet.subSet(first, false, BigInteger.ONE, false);
312			}
313
314			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
315			public void testheadSetRanges(String description, NavigableSet navigableSet) {
316			NavigableSet subSet = navigableSet.headSet(BigInteger.ONE, true);
317
318			// same subset
319			subSet.headSet(BigInteger.ONE, true);
320
321			// slightly smaller
322			NavigableSet ns = subSet.headSet(BigInteger.ONE, false);
323
324	jsr166	1.2	// slight expansion
325	jsr166	1.1	assertThrows(() -> {
326			ns.headSet(BigInteger.ONE, true);
327			},
328			IllegalArgumentException.class,
329			description + ": Expansion should not be allowed");
330
331			// much smaller
332			subSet.headSet(isDescending(subSet) ? BigInteger.TEN : BigInteger.ZERO, true);
333			}
334
335			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
336			public void testTailSetRanges(String description, NavigableSet navigableSet) {
337			NavigableSet subSet = navigableSet.tailSet(BigInteger.ONE, true);
338
339			// same subset
340			subSet.tailSet(BigInteger.ONE, true);
341
342			// slightly smaller
343			NavigableSet ns = subSet.tailSet(BigInteger.ONE, false);
344
345	jsr166	1.2	// slight expansion
346	jsr166	1.1	assertThrows(() -> {
347			ns.tailSet(BigInteger.ONE, true);
348			},
349			IllegalArgumentException.class,
350			description + ": Expansion should not be allowed");
351
352			// much smaller
353			subSet.tailSet(isDescending(subSet) ? BigInteger.ZERO : BigInteger.TEN, false);
354			}
355
356			/**
357			* Tests the tailSet() method.
358			*/
359			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
360			public void testTailSet(String description, NavigableSet navigableSet) {
361			assertThrows(() -> {
362			navigableSet.tailSet(null);
363			},
364			NullPointerException.class,
365			description + ": Must throw NullPointerException for null element");
366
367			assertThrows(() -> {
368			navigableSet.tailSet(new Object());
369			}, ClassCastException.class);
370
371			NavigableSet ss = navigableSet.tailSet("1", true);
372
373			assertEmptyNavigableSet(ss, description + ": Returned value is not empty navigable set.");
374			}
375
376			/**
377			* Tests that the array has a size of 0.
378			*/
379			@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
380			public void testToArray(String description, NavigableSet<?> navigableSet) {
381			Object[] emptyNavigableSetArray = navigableSet.toArray();
382
383			assertTrue(emptyNavigableSetArray.length == 0, "Returned non-empty Array.");
384
385			emptyNavigableSetArray = new Object[20];
386
387			Object[] result = navigableSet.toArray(emptyNavigableSetArray);
388
389			assertSame(emptyNavigableSetArray, result);
390
391			assertTrue(result[0] == null);
392			}
393
394			@DataProvider(name = "NavigableSet<?>", parallel = true)
395			public static Iterator<Object[]> navigableSetsProvider() {
396			return makeNavigableSets().iterator();
397			}
398
399			public static Collection<Object[]> makeNavigableSets() {
400			return Arrays.asList(
401			new Object[]{"UnmodifiableNavigableSet(TreeSet)", Collections.unmodifiableNavigableSet(new TreeSet())},
402			new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet())},
403			new Object[]{"UnmodifiableNavigableSet(TreeSet.descendingSet().descendingSet()", Collections.unmodifiableNavigableSet(new TreeSet().descendingSet().descendingSet())},
404			new Object[]{"emptyNavigableSet()", Collections.emptyNavigableSet()},
405			new Object[]{"emptyNavigableSet().descendingSet()", Collections.emptyNavigableSet().descendingSet()},
406			new Object[]{"emptyNavigableSet().descendingSet().descendingSet()", Collections.emptyNavigableSet().descendingSet().descendingSet()}
407			);
408			}
409			}