refactor: BubbleSortRecursion: improving naming, adding standard test (#5267)

* refactor: improving naming, adding standard test

* style: remove `BubbleSortRecursive` from pmd exclude list

* docs: typo fix

---------

Co-authored-by: Alex Klymenko <alx@alx.com>
Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com>

DIRECTORY.md

@@ -490,7 +490,7 @@
             * [BitonicSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BitonicSort.java)
             * [BogoSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BogoSort.java)
             * [BubbleSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BubbleSort.java)
-            * [BubbleSortRecursion](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BubbleSortRecursion.java)
+            * [BubbleSortRecursive](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BubbleSortRecursive.java)
             * [BucketSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/BucketSort.java)
             * [CircleSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/CircleSort.java)
             * [CocktailShakerSort](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/sorts/CocktailShakerSort.java)
@@ -859,6 +859,7 @@
             * [BinaryInsertionSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BinaryInsertionSortTest.java)
             * [BogoSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BogoSortTest.java)
             * [BubbleSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BubbleSortTest.java)
+            * [BubbleSortRecursiveTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BubbleSortRecursiveTest.java)
             * [BucketSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/BucketSortTest.java)
             * [CircleSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/CircleSortTest.java)
             * [CocktailShakerSortTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/sorts/CocktailShakerSortTest.java)

pmd-exclude.properties

@@ -76,7 +76,6 @@ com.thealgorithms.searches.InterpolationSearch=UselessParentheses
 com.thealgorithms.searches.KMPSearch=UselessParentheses
 com.thealgorithms.searches.LinearSearchThread=EmptyCatchBlock
 com.thealgorithms.searches.RabinKarpAlgorithm=UselessParentheses
-com.thealgorithms.sorts.BubbleSortRecursion=UselessParentheses
 com.thealgorithms.sorts.CircleSort=EmptyControlStatement
 com.thealgorithms.sorts.CombSort=UselessParentheses
 com.thealgorithms.sorts.DutchNationalFlagSort=UselessParentheses

src/main/java/com/thealgorithms/sorts/BubbleSortRecursion.java

@@ -1,57 +0,0 @@
-package com.thealgorithms.sorts;
-
-import java.util.Random;
-
-/**
- * BubbleSort algorithm implements using recursion
- */
-public class BubbleSortRecursion implements SortAlgorithm {
-
-    public static void main(String[] args) {
-        Integer[] array = new Integer[10];
-
-        Random random = new Random();
-        /* generate 10 random numbers from -50 to 49 */
-        for (int i = 0; i < array.length; ++i) {
-            array[i] = random.nextInt(100) - 50;
-        }
-
-        BubbleSortRecursion bubbleSortRecursion = new BubbleSortRecursion();
-        bubbleSortRecursion.sort(array);
-
-        /* check array is sorted or not */
-        for (int i = 0; i < array.length - 1; ++i) {
-            assert (array[i].compareTo(array[i + 1]) <= 0);
-        }
-    }
-
-    /**
-     * @param unsorted - an array should be sorted
-     * @return sorted array
-     */
-    @Override
-    public <T extends Comparable<T>> T[] sort(T[] unsorted) {
-        bubbleSort(unsorted, unsorted.length);
-        return unsorted;
-    }
-
-    /**
-     * BubbleSort algorithm implements using recursion
-     *
-     * @param unsorted array contains elements
-     * @param len length of given array
-     */
-    private static <T extends Comparable<T>> void bubbleSort(T[] unsorted, int len) {
-        boolean swapped = false;
-        /* flag to check if array is sorted or not */
-        for (int i = 0; i < len - 1; ++i) {
-            if (SortUtils.greater(unsorted[i], unsorted[i + 1])) {
-                SortUtils.swap(unsorted, i, i + 1);
-                swapped = true;
-            }
-        }
-        if (swapped) {
-            bubbleSort(unsorted, len - 1);
-        }
-    }
-}

src/main/java/com/thealgorithms/sorts/BubbleSortRecursive.java

@@ -0,0 +1,35 @@
+package com.thealgorithms.sorts;
+
+/**
+ * BubbleSort algorithm implemented using recursion
+ */
+public class BubbleSortRecursive implements SortAlgorithm {
+    /**
+     * @param array - an array should be sorted
+     * @return sorted array
+     */
+    @Override
+    public <T extends Comparable<T>> T[] sort(T[] array) {
+        bubbleSort(array, array.length);
+        return array;
+    }
+
+    /**
+     * BubbleSort algorithm implements using recursion
+     *
+     * @param array array contains elements
+     * @param len length of given array
+     */
+    private static <T extends Comparable<T>> void bubbleSort(T[] array, int len) {
+        boolean swapped = false;
+        for (int i = 0; i < len - 1; ++i) {
+            if (SortUtils.greater(array[i], array[i + 1])) {
+                SortUtils.swap(array, i, i + 1);
+                swapped = true;
+            }
+        }
+        if (swapped) {
+            bubbleSort(array, len - 1);
+        }
+    }
+}

src/test/java/com/thealgorithms/sorts/BubbleSortRecursiveTest.java

@@ -0,0 +1,8 @@
+package com.thealgorithms.sorts;
+
+public class BubbleSortRecursiveTest extends SortingAlgorithmTest {
+    @Override
+    SortAlgorithm getSortAlgorithm() {
+        return new BubbleSortRecursive();
+    }
+}