From 651992cfd65b2c835bf04e451610b092ed7ec05e Mon Sep 17 00:00:00 2001
From: Cristiano Jesus <crist.borges05@gmail.com>
Date: Tue, 19 Apr 2022 23:58:12 +0100
Subject: [PATCH] feat: Code refactor for AbsoluteMin improvements

I'm refactoring some classes from the `maths` package to have a cleaner,
more concise, easier to maintain and better documented code.

I've also updated the code to use features from newer versions of Java
and I've created some unit tests because it was missing unit tests for
AbsoluteMin (I'm using now unit tests instead of main method to test the
feature).

Resolves: #3021
---
 .../com/thealgorithms/maths/AbsoluteMin.java  | 44 +++++++++----------
 .../thealgorithms/maths/AbsoluteMinTest.java  | 21 +++++++++
 2 files changed, 41 insertions(+), 24 deletions(-)
 create mode 100644 src/test/java/com/thealgorithms/maths/AbsoluteMinTest.java

diff --git a/src/main/java/com/thealgorithms/maths/AbsoluteMin.java b/src/main/java/com/thealgorithms/maths/AbsoluteMin.java
index bdb8eb1a9740..9b6f0e747d5f 100644
--- a/src/main/java/com/thealgorithms/maths/AbsoluteMin.java
+++ b/src/main/java/com/thealgorithms/maths/AbsoluteMin.java
@@ -2,35 +2,31 @@
 
 import java.util.Arrays;
 
-/**
- * description:
- *
- * <p>
- * absMin([0, 5, 1, 11]) = 0, absMin([3 , -10, -2]) = -2
- */
 public class AbsoluteMin {
 
-    public static void main(String[] args) {
-        int[] testnums = {4, 0, 16};
-        assert absMin(testnums) == 0;
-
-        int[] numbers = {3, -10, -2};
-        System.out.println("absMin(" + Arrays.toString(numbers) + ") = " + absMin(numbers));
-    }
-
     /**
-     * get the value, returns the absolute min value min
+     * Compares the numbers given as arguments to get the absolute min value.
      *
-     * @param numbers contains elements
-     * @return the absolute min value
+     * @param numbers The numbers to compare
+     * @return The absolute min value
      */
-    public static int absMin(int[] numbers) {
-        int absMinValue = numbers[0];
-        for (int i = 1, length = numbers.length; i < length; ++i) {
-            if (Math.abs(numbers[i]) < Math.abs(absMinValue)) {
-                absMinValue = numbers[i];
-            }
+    public static int getMinValue(int... numbers) {
+        if (numbers.length == 0) {
+            throw new IllegalArgumentException("Numbers array cannot be empty");
         }
-        return absMinValue;
+
+        var absMinWrapper = new Object() {
+            int value = numbers[0];
+        };
+
+        Arrays.stream(numbers)
+                .skip(1)
+                .forEach(number -> {
+                    if (Math.abs(number) < Math.abs(absMinWrapper.value)) {
+                        absMinWrapper.value = number;
+                    }
+                });
+
+        return absMinWrapper.value;
     }
 }
diff --git a/src/test/java/com/thealgorithms/maths/AbsoluteMinTest.java b/src/test/java/com/thealgorithms/maths/AbsoluteMinTest.java
new file mode 100644
index 000000000000..571b080cd866
--- /dev/null
+++ b/src/test/java/com/thealgorithms/maths/AbsoluteMinTest.java
@@ -0,0 +1,21 @@
+package com.thealgorithms.maths;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+public class AbsoluteMinTest {
+
+    @Test
+    void testGetMinValue() {
+        assertEquals(0, AbsoluteMin.getMinValue(4, 0, 16));
+        assertEquals(-2, AbsoluteMin.getMinValue(3, -10, -2));
+    }
+
+    @Test
+    void testGetMinValueWithNoArguments() {
+        Exception exception = assertThrows(IllegalArgumentException.class, () -> AbsoluteMin.getMinValue());
+        assertEquals("Numbers array cannot be empty", exception.getMessage());
+    }
+}