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, 8 months ago) by jsr166
Branch:	MAIN
Changes since 1.3:	+1 -2 lines
Log Message:	tidy imports
#	Content
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	import static org.testng.Assert.assertTrue;
47
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	+ ": Must throw IllegalArgumentException when fromElement is not less than toElement.");
287
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	// slight expansion
304	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	// slight expansion
325	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	// slight expansion
346	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	}