Create StalinSortTest.java

Author: anant-jain01

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

@@ -0,0 +1,83 @@
+package com.thealgorithms.sorts;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.stream.Stream;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+public class StalinSortTest {
+
+    @ParameterizedTest
+    @MethodSource("provideArraysForStalinSort")
+    public void testStalinSort(Comparable[] inputArray, Comparable[] expectedArray) {
+        StalinSort stalinSort = new StalinSort();
+        assertArrayEquals(expectedArray, stalinSort.sort(inputArray));
+    }
+
+    private static Stream<Arguments> provideArraysForStalinSort() {
+        return Stream.of(
+            // Test empty array
+            Arguments.of(new Integer[] {}, new Integer[] {}),
+
+            // Test single element array
+            Arguments.of(new Integer[] {4}, new Integer[] {4}),
+
+            // Test array with multiple elements
+            Arguments.of(new Integer[] {4, 23, 6, 78, 1, 54, 231, 9, 12}, new Integer[] {4, 23, 78, 231}),
+            Arguments.of(new Integer[] {5, 5, 5, 5, 5}, new Integer[] {5, 5, 5, 5, 5}),
+            Arguments.of(new Integer[] {1, 2, 3, 4, 5}, new Integer[] {1, 2, 3, 4, 5}),
+            Arguments.of(new Integer[] {5, 4, 3, 2, 1}, new Integer[] {5}),
+            Arguments.of(new String[] {"c", "a", "e", "b", "d"}, new String[] {"c", "e"}),
+
+            // Test with negative numbers
+            Arguments.of(new Integer[] {-1, -2, -3, 4, 5}, new Integer[] {-1, 4, 5}),
+            Arguments.of(new Integer[] {0, -1, -2, 1, 2}, new Integer[] {0, 1, 2}),
+
+            // Test mixed values (positive, negative, zero)
+            Arguments.of(new Integer[] {3, -1, 0, -5, 2}, new Integer[] {3}),
+
+            // Test with duplicate values
+            Arguments.of(new Integer[] {10, 10, 10, 10}, new Integer[] {10, 10, 10, 10}),
+            Arguments.of(new Integer[] {1, 2, 2, 3, 3, 3, 4}, new Integer[] {1, 2, 2, 3, 3, 3, 4}),
+            
+            // Test large numbers
+            Arguments.of(new Integer[] {Integer.MAX_VALUE, Integer.MIN_VALUE, 0}, new Integer[] {Integer.MAX_VALUE}),
+            
+            // Test with characters
+            Arguments.of(new Character[] {'d', 'a', 'c', 'b'}, new Character[] {'d'}),
+            
+            // Test with a large dataset
+            Arguments.of(new Integer[] {100, 200, 150, 300, 250, 400, 350, 450, 500}, new Integer[] {100, 200, 300, 400, 500})
+        );
+    }
+
+    @Test
+    public void testWithEmptyArray() {
+        StalinSort stalinSort = new StalinSort();
+        Integer[] inputArray = {};
+        Integer[] expectedArray = {};
+        assertArrayEquals(expectedArray, stalinSort.sort(inputArray));
+    }
+
+    @Test
+    public void testWithNullValues() {
+        assertThrows(NullPointerException.class, () -> {
+            StalinSort stalinSort = new StalinSort();
+            stalinSort.sort(null);
+        });
+    }
+
+    @Test
+    public void testWithMixedDataTypes() {
+        // This test checks the algorithm's capability with mixed types, if applicable.
+        // Note: Ensure that your algorithm is capable of handling mixed types; if not, this test will fail.
+        assertThrows(ClassCastException.class, () -> {
+            StalinSort stalinSort = new StalinSort();
+            stalinSort.sort(new Comparable[] {"a", 1});
+        });
+    }
+}