Add PhraseHighlightComparatorTest

Author: idodeclare

src/org/opensolaris/opengrok/search/context/PhraseHighlightComparator.java

@@ -33,21 +33,36 @@ public class PhraseHighlightComparator implements Comparator<PhraseHighlight> {
     public static final PhraseHighlightComparator INSTANCE =
         new PhraseHighlightComparator();
 
+    /**
+     * Compares two {@link PhraseHighlight} instances for order by first
+     * comparing using {@link Integer#compare(int, int)} the
+     * {@link PhraseHighlight#lineStart} values of {@code o1} and {@code o2} and
+     * subsequently, if identical, comparing the {@link PhraseHighlight#lineEnd}
+     * values of {@code o2} and {@code o1} (i.e. inverted).
+     * <p>The ordering allows to iterate through a collection afterward and
+     * easily subsume where necessary a {@link PhraseHighlight} instance into
+     * its immediate predecessor.
+     * @param o1 a required instance
+     * @param o2 a required instance
+     * @return a negative integer, zero, or a positive integer as the first
+     * argument is less than, equal to, or greater than the second
+     */
     @Override
     public int compare(PhraseHighlight o1, PhraseHighlight o2) {
-        // ASC by lineStart, with -1 == -Inf.
+        int cmp;
         if (o1.getLineStart() < 0) {
             if (o2.getLineStart() >= 0) {
                 return -1;
             }
+            cmp = 0;
         } else if (o2.getLineStart() < 0) {
             return 1;
+        } else {
+            cmp = Integer.compare(o1.getLineStart(), o2.getLineStart());
         }
-        int cmp = Integer.compare(o1.getLineStart(), o2.getLineStart());
         if (cmp != 0) {
             return cmp;
         }
-        // DESC by lineEnd, with -1 == Inf.
         cmp = Integer.compare(o2.getLineEnd(), o1.getLineEnd());
         return cmp;
     }

test/org/opensolaris/opengrok/search/context/PhraseHighlightComparatorTest.java

@@ -0,0 +1,148 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * See LICENSE.txt included in this distribution for the specific
+ * language governing permissions and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at LICENSE.txt.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2018, Chris Fraire <[email protected]>.
+ */
+
+package org.opensolaris.opengrok.search.context;
+
+import static org.junit.Assert.assertEquals;
+import org.junit.Test;
+
+/**
+ * Represents a container of tests of {@link PhraseHighlightComparator}.
+ */
+public class PhraseHighlightComparatorTest {
+
+    private PhraseHighlight o1;
+    private PhraseHighlight o2;
+
+    @Test
+    public void testEqualBoundedInstances() {
+        o1 = PhraseHighlight.create(0, 1);
+        o2 = PhraseHighlight.create(0, 1);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[0,1] should be == o2[0,1]", 0, result);
+    }
+
+    @Test
+    public void testEqualUnboundedInstances() {
+        o1 = PhraseHighlight.createEntire();
+        o2 = PhraseHighlight.createEntire();
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[,] should be == o2[,]", 0, result);
+    }
+
+    @Test
+    public void testEqualMixedBoundedInstances1() {
+        o1 = PhraseHighlight.createStarter(5);
+        o2 = PhraseHighlight.createStarter(5);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[5,] should be == o2[5,]", 0, result);
+    }
+
+    @Test
+    public void testEqualMixedBoundedInstances2() {
+        o1 = PhraseHighlight.createEnder(5);
+        o2 = PhraseHighlight.createEnder(5);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[,5] should be == o2[,5]", 0, result);
+    }
+
+    @Test
+    public void testDisjointInstances1() {
+        o1 = PhraseHighlight.create(0, 10);
+        o2 = PhraseHighlight.create(100, 110);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[0,10] should be < o2[100,110]", -1, result);
+    }
+
+    @Test
+    public void testDisjointInstances2() {
+        o1 = PhraseHighlight.create(2, 3);
+        o2 = PhraseHighlight.create(0, 2);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[2,3] should be > o2[0,2]", 1, result);
+    }
+
+    @Test
+    public void testBoundedOverlappingUnequalInstances1() {
+        o1 = PhraseHighlight.create(0, 10);
+        o2 = PhraseHighlight.create(1, 3);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[0,10] should be < o2[1,3]", -1, result);
+    }
+
+    @Test
+    public void testBoundedOverlappingUnequalInstances2() {
+        o1 = PhraseHighlight.create(0, 5);
+        o2 = PhraseHighlight.create(0, 10);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[0,5] should be > o2[0,10]", 1, result);
+    }
+
+    @Test
+    public void testBoundedOverlappingUnequalInstances3() {
+        o1 = PhraseHighlight.create(5, 15);
+        o2 = PhraseHighlight.create(0, 10);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[5,15] should be > o2[0,10]", 1, result);
+    }
+
+    @Test
+    public void testBoundedOverlappingUnequalInstances4() {
+        o1 = PhraseHighlight.create(0, 10);
+        o2 = PhraseHighlight.create(5, 10);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[0,10] should be < o2[5,10]", -1, result);
+    }
+
+    @Test
+    public void testMixedBoundedNonOverlappingInstances1() {
+        o1 = PhraseHighlight.createEnder(10);
+        o2 = PhraseHighlight.create(15, 30);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[,10] should be < o2[15,30]", -1, result);
+    }
+
+    @Test
+    public void testMixedBoundedNonOverlappingInstances2() {
+        o1 = PhraseHighlight.createStarter(15);
+        o2 = PhraseHighlight.create(0, 10);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[15,] should be > o2[0,10]", 1, result);
+    }
+
+    @Test
+    public void testMixedBoundedOverlappingInstances1() {
+        o1 = PhraseHighlight.createEnder(20);
+        o2 = PhraseHighlight.create(15, 30);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[,20] should be < o2[15,30]", -1, result);
+    }
+
+    @Test
+    public void testMixedBoundedOverlappingInstances2() {
+        o1 = PhraseHighlight.createStarter(20);
+        o2 = PhraseHighlight.create(15, 30);
+        int result = PhraseHighlightComparator.INSTANCE.compare(o1, o2);
+        assertEquals("o1[20,] should be > o2[15,30]", 1, result);
+    }
+}