tests: add tests of Mode

Author: vil02

src/main/java/com/thealgorithms/maths/Mode.java

@@ -1,7 +1,6 @@
 package com.thealgorithms.maths;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 
@@ -11,15 +10,8 @@
  * The mode of an array of numbers is the most frequently occurring number in the array,
  * or the most frequently occurring numbers if there are multiple numbers with the same frequency
  */
-public class Mode {
-
-    public static void main(String[] args) {
-        /* Test array of integers */
-        assert (mode(new int[] {})) == null;
-        assert Arrays.equals(mode(new int[] {5}), new int[] {5});
-        assert Arrays.equals(mode(new int[] {1, 2, 3, 4, 5}), new int[] {1, 2, 3, 4, 5});
-        assert Arrays.equals(mode(new int[] {7, 9, 9, 4, 5, 6, 7, 7, 8}), new int[] {7});
-        assert Arrays.equals(mode(new int[] {7, 9, 9, 4, 5, 6, 7, 7, 9}), new int[] {7, 9});
+public final class Mode {
+    private Mode() {
     }
 
     /*
@@ -28,7 +20,7 @@ public static void main(String[] args) {
      * @param numbers array of integers
      * @return mode of the array
      */
-    public static int[] mode(int[] numbers) {
+    public static int[] mode(final int[] numbers) {
         if (numbers.length == 0) {
             return null;
         }

src/test/java/com/thealgorithms/maths/ModeTest.java

@@ -0,0 +1,21 @@
+package com.thealgorithms.maths;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+
+import java.util.stream.Stream;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
+public class ModeTest {
+    @ParameterizedTest
+    @MethodSource("tcStream")
+    void basicTest(final int[] expected, final int[] numbers) {
+        assertArrayEquals(expected, Mode.mode(numbers));
+    }
+
+    private static Stream<Arguments> tcStream() {
+        return Stream.of(Arguments.of(null, new int[] {}), Arguments.of(new int[] {5}, new int[] {5}), Arguments.of(new int[] {1, 2, 3, 4, 5}, new int[] {1, 2, 3, 4, 5}), Arguments.of(new int[] {1, 2, 3, 4, 5}, new int[] {5, 4, 3, 2, 1}),
+            Arguments.of(new int[] {7}, new int[] {7, 9, 9, 4, 5, 6, 7, 7, 8}), Arguments.of(new int[] {7, 9}, new int[] {7, 9, 9, 4, 5, 6, 7, 7, 9}));
+    }
+}