--- jsr166/src/test/tck/LinkedListTest.java	2015/05/23 00:53:08	1.39
+++ jsr166/src/test/tck/LinkedListTest.java	2018/05/28 21:19:50	1.48
@@ -10,10 +10,11 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.NoSuchElementException;
+import java.util.concurrent.ThreadLocalRandom;
 
 import junit.framework.Test;
-import junit.framework.TestSuite;
 
 public class LinkedListTest extends JSR166TestCase {
     public static void main(String[] args) {
@@ -21,20 +22,42 @@ public class LinkedListTest extends JSR1
     }
 
     public static Test suite() {
-        return new TestSuite(LinkedListTest.class);
+        class Implementation implements CollectionImplementation {
+            public Class<?> klazz() { return LinkedList.class; }
+            public List emptyCollection() { return new LinkedList(); }
+            public Object makeElement(int i) { return i; }
+            public boolean isConcurrent() { return false; }
+            public boolean permitsNulls() { return true; }
+        }
+        class SubListImplementation extends Implementation {
+            public List emptyCollection() {
+                List list = super.emptyCollection();
+                ThreadLocalRandom rnd = ThreadLocalRandom.current();
+                if (rnd.nextBoolean())
+                    list.add(makeElement(rnd.nextInt()));
+                int i = rnd.nextInt(list.size() + 1);
+                return list.subList(i, i);
+            }
+        }
+        return newTestSuite(
+                LinkedListTest.class,
+                CollectionTest.testSuite(new Implementation()),
+                CollectionTest.testSuite(new SubListImplementation()));
     }
 
     /**
      * Returns a new queue of given size containing consecutive
-     * Integers 0 ... n.
+     * Integers 0 ... n - 1.
      */
-    private LinkedList<Integer> populatedQueue(int n) {
-        LinkedList<Integer> q = new LinkedList<Integer>();
+    private static LinkedList<Integer> populatedQueue(int n) {
+        LinkedList<Integer> q = new LinkedList<>();
         assertTrue(q.isEmpty());
         for (int i = 0; i < n; ++i)
             assertTrue(q.offer(new Integer(i)));
         assertFalse(q.isEmpty());
         assertEquals(n, q.size());
+        assertEquals((Integer) 0, q.peekFirst());
+        assertEquals((Integer) (n - 1), q.peekLast());
         return q;
     }
 
@@ -243,14 +266,14 @@ public class LinkedListTest extends JSR1
             assertTrue(q.contains(i));
             assertTrue(q.remove((Integer)i));
             assertFalse(q.contains(i));
-            assertTrue(q.contains(i-1));
+            assertTrue(q.contains(i - 1));
         }
         for (int i = 0; i < SIZE; i += 2) {
             assertTrue(q.contains(i));
             assertTrue(q.remove((Integer)i));
             assertFalse(q.contains(i));
-            assertFalse(q.remove((Integer)(i+1)));
-            assertFalse(q.contains(i+1));
+            assertFalse(q.remove((Integer)(i + 1)));
+            assertFalse(q.contains(i + 1));
         }
         assertTrue(q.isEmpty());
     }
@@ -335,9 +358,11 @@ public class LinkedListTest extends JSR1
      */
     public void testToArray() {
         LinkedList q = populatedQueue(SIZE);
-        Object[] o = q.toArray();
-        for (int i = 0; i < o.length; i++)
-            assertSame(o[i], q.poll());
+        Object[] a = q.toArray();
+        assertSame(Object[].class, a.getClass());
+        for (Object o : a)
+            assertSame(o, q.poll());
+        assertTrue(q.isEmpty());
     }
 
     /**
@@ -348,8 +373,9 @@ public class LinkedListTest extends JSR1
         Integer[] ints = new Integer[SIZE];
         Integer[] array = q.toArray(ints);
         assertSame(ints, array);
-        for (int i = 0; i < ints.length; i++)
-            assertSame(ints[i], q.poll());
+        for (Integer o : ints)
+            assertSame(o, q.poll());
+        assertTrue(q.isEmpty());
     }
 
     /**
@@ -619,7 +645,7 @@ public class LinkedListTest extends JSR1
         }
         for (int i = 0; i < SIZE; i += 2) {
             assertTrue(q.removeFirstOccurrence(new Integer(i)));
-            assertFalse(q.removeFirstOccurrence(new Integer(i+1)));
+            assertFalse(q.removeFirstOccurrence(new Integer(i + 1)));
         }
         assertTrue(q.isEmpty());
     }
@@ -634,7 +660,7 @@ public class LinkedListTest extends JSR1
         }
         for (int i = 0; i < SIZE; i += 2) {
             assertTrue(q.removeLastOccurrence(new Integer(i)));
-            assertFalse(q.removeLastOccurrence(new Integer(i+1)));
+            assertFalse(q.removeLastOccurrence(new Integer(i + 1)));
         }
         assertTrue(q.isEmpty());
     }