[test] Added test cases for sub list

Author: mta452

tehreer-android/src/test/java/com/mta/tehreer/collections/IntListTestSuite.java

@@ -27,6 +27,13 @@ public abstract class IntListTestSuite {
     protected IntList actual;
     protected int[] expected;
 
+    private static class SubListTestSuite extends IntListTestSuite {
+        SubListTestSuite(IntList subList, int[] expected) {
+            this.actual = subList;
+            this.expected = expected;
+        }
+    }
+
     protected IntListTestSuite() {
     }
 
@@ -37,7 +44,8 @@ public void testSize() {
 
     @Test
     public void testElements() {
-        for (int i = 0; i < expected.length; i++) {
+        int length = expected.length;
+        for (int i = 0; i < length; i++) {
             assertEquals(actual.get(i), expected[i]);
         }
     }
@@ -82,6 +90,58 @@ public void testCopyAtEnd() {
         assertArrayEquals(copiedChunk, expected);
     }
 
+    private static void testSubList(IntList subList, int[] expected) {
+        SubListTestSuite suite = new SubListTestSuite(subList, expected);
+        suite.testSize();
+        suite.testElements();
+        suite.testCopyFull();
+        suite.testCopyAtStart();
+        suite.testCopyAtEnd();
+        suite.testToArray();
+        suite.testEquals();
+    }
+
+    @Test
+    public void testSubListEmpty() {
+        int fullLength = expected.length;
+        int halfLength = fullLength / 2;
+
+        testSubList(actual.subList(0, 0), new int[0]);
+        testSubList(actual.subList(halfLength, halfLength), new int[0]);
+        testSubList(actual.subList(fullLength, fullLength), new int[0]);
+    }
+
+    @Test
+    public void testSubListFirstHalf() {
+        int firstStart = 0;
+        int firstEnd = expected.length / 2;
+        int[] firstHalf = Arrays.copyOfRange(expected, firstStart, firstEnd);
+        IntList subList = actual.subList(firstStart, firstEnd);
+
+        testSubList(subList, firstHalf);
+    }
+
+    @Test
+    public void testSubListSecondHalf() {
+        int secondStart = expected.length / 2;
+        int secondEnd = expected.length;
+        int[] secondHalf = Arrays.copyOfRange(expected, secondStart, secondEnd);
+        IntList subList = actual.subList(secondStart, secondEnd);
+
+        testSubList(subList, secondHalf);
+    }
+
+    @Test
+    public void testSubListMidHalf() {
+        int halfLength = expected.length / 2;
+        int midStart = halfLength / 2;
+        int midEnd = midStart + halfLength;
+        int[] midHalf = Arrays.copyOfRange(expected, midStart, midEnd);
+        IntList subList = actual.subList(midStart, midEnd);
+
+        testSubList(subList, midHalf);
+    }
+
     @Test
     public void testToArray() {
         assertArrayEquals(actual.toArray(), expected);