Add tests for Average (TheAlgorithms#3652)

Author: PhilippeCancellier

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

@@ -5,25 +5,6 @@
  */
 public class Average {
 
-    private static final double SMALL_VALUE = 0.00001f;
-
-    public static void main(String[] args) {
-        assert Math.abs(
-            average(new double[] { 3, 6, 9, 12, 15, 18, 21 }) - 12
-        ) <
-        SMALL_VALUE;
-        assert Math.abs(
-            average(new double[] { 5, 10, 15, 20, 25, 30, 35 }) - 20
-        ) <
-        SMALL_VALUE;
-        assert Math.abs(
-            average(new double[] { 1, 2, 3, 4, 5, 6, 7, 8 }) - 4.5
-        ) <
-        SMALL_VALUE;
-        int[] array = { 2, 4, 10 };
-        assert average(array) == 5;
-    }
-
     /**
      * Calculate average of a list of numbers
      *
@@ -41,15 +22,15 @@ public static double average(double[] numbers) {
     /**
      * find average value of int array
      *
-     * @param array the array contains element and the sum does not excess long
-     * value limit
+     * @param numbers the array contains element and the sum does not excess long
+     *                value limit
      * @return average value
      */
-    public static int average(int[] array) {
+    public static int average(int[] numbers) {
         long sum = 0;
-        for (int i = 0; i < array.length; ++i) {
-            sum += array[i];
+        for (int number : numbers) {
+            sum += number;
         }
-        return (int) (sum / array.length);
+        return (int) (sum / numbers.length);
     }
 }

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

@@ -5,10 +5,30 @@
 
 public class AverageTest {
 
-    double[] numbers = { 3, 6, 9, 12, 15, 18, 21 };
+    private static final double SMALL_VALUE = 0.00001d;
 
     @Test
-    public void testAverage() {
-        Assertions.assertEquals(12, Average.average(numbers));
+    public void testAverage_double_12() {
+        double[] numbers = {3d, 6d, 9d, 12d, 15d, 18d, 21d};
+        Assertions.assertEquals(12d, Average.average(numbers), SMALL_VALUE);
     }
+
+    @Test
+    public void testAverage_double_20() {
+        double[] numbers = {5d, 10d, 15d, 20d, 25d, 30d, 35d};
+        Assertions.assertEquals(20d, Average.average(numbers), SMALL_VALUE);
+    }
+
+    @Test
+    public void testAverage_double_4_5() {
+        double[] numbers = {1d, 2d, 3d, 4d, 5d, 6d, 7d, 8d};
+        Assertions.assertEquals(4.5d, Average.average(numbers), SMALL_VALUE);
+    }
+
+    @Test
+    public void testAverage_int_5() {
+        int[] numbers = {2, 4, 10};
+        Assertions.assertEquals(5, Average.average(numbers));
+    }
+
 }