Add palindrome checker using stack (#5887)

src/test/java/com/thealgorithms/stacks/PalindromeWithStackTest.java

@@ -0,0 +1,77 @@
+package com.thealgorithms.stacks;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class PalindromeWithStackTest {
+
+    private PalindromeWithStack palindromeChecker;
+
+    @BeforeEach
+    public void setUp() {
+        palindromeChecker = new PalindromeWithStack();
+    }
+
+    @Test
+    public void testValidOne() {
+        String testString = "Racecar";
+        assertTrue(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testInvalidOne() {
+        String testString = "James";
+        assertFalse(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testValidTwo() {
+        String testString = "madam";
+        assertTrue(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testInvalidTwo() {
+        String testString = "pantry";
+        assertFalse(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testValidThree() {
+        String testString = "RaDar";
+        assertTrue(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testInvalidThree() {
+        String testString = "Win";
+        assertFalse(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testBlankString() {
+        String testString = "";
+        assertTrue(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testStringWithNumbers() {
+        String testString = "12321";
+        assertTrue(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testStringWithNumbersTwo() {
+        String testString = "12325";
+        assertFalse(palindromeChecker.checkPalindrome(testString));
+    }
+
+    @Test
+    public void testStringWithNumbersAndLetters() {
+        String testString = "po454op";
+        assertTrue(palindromeChecker.checkPalindrome(testString));
+    }
+}