Code refactor for AbsoluteValue improvements (#3018)

Fix #3017

Co-authored-by: Yang Libin <szuyanglb@outlook.com>

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

@@ -1,26 +1,14 @@
 package com.thealgorithms.maths;
 
-import java.util.Random;
-
 public class AbsoluteValue {
 
-    public static void main(String[] args) {
-        Random random = new Random();
-
-        /* test 1000 random numbers */
-        for (int i = 1; i <= 1000; ++i) {
-            int randomNumber = random.nextInt();
-            assert absVal(randomNumber) == Math.abs(randomNumber);
-        }
-    }
-
     /**
-     * If value is less than zero, make value positive.
+     * Returns the absolute value of a number.
      *
-     * @param value a number
-     * @return the absolute value of a number
+     * @param number The number to be transformed
+     * @return The absolute value of the {@code number}
      */
-    public static int absVal(int value) {
-        return value < 0 ? -value : value;
+    public static int getAbsValue(int number) {
+        return number < 0 ? -number : number;
     }
 }

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

@@ -0,0 +1,18 @@
+package com.thealgorithms.maths;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.stream.Stream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class AbsoluteValueTest {
+
+    @Test
+    void testGetAbsValue() {
+        Stream.generate(() -> ThreadLocalRandom.current().nextInt())
+                .limit(1000)
+                .forEach(number -> assertEquals(Math.abs(number), AbsoluteValue.getAbsValue(number)));
+    }
+}