Refactor AtbashCipher, add ParameterizedTest (#5808)

src/test/java/com/thealgorithms/ciphers/AtbashTest.java

@@ -2,27 +2,42 @@ package com.thealgorithms.ciphers;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-import org.junit.jupiter.api.Test;
+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 AtbashTest {
 
-    @Test
-    public void atbashEncrypt() {
-        AtbashCipher normalToEncrypt = new AtbashCipher("Hello World! 123, @cipher abcDEF ZYX 987 madam zzZ Palindrome!");
-        String expectedText = "Svool Dliow! 123, @xrksvi zyxWVU ABC 987 nzwzn aaA Kzormwilnv!";
-
-        normalToEncrypt.setString(normalToEncrypt.convert());
-
-        assertEquals(expectedText, normalToEncrypt.getString());
+    @ParameterizedTest
+    @MethodSource("cipherTestProvider")
+    public void testAtbashCipher(String input, String expected) {
+        AtbashCipher cipher = new AtbashCipher(input);
+        assertEquals(expected, cipher.convert());
     }
 
-    @Test
-    public void atbashDecrypt() {
-        AtbashCipher encryptToNormal = new AtbashCipher("Svool Dliow! 123, @xrksvi zyxWVU ABC 987 nzwzn aaA Kzormwilnv!");
-        String expectedText = "Hello World! 123, @cipher abcDEF ZYX 987 madam zzZ Palindrome!";
+    private static Stream<Arguments> cipherTestProvider() {
+        return Stream.of(
+            // Basic tests with lowercase and uppercase
+            Arguments.of("Hello", "Svool"), Arguments.of("WORLD", "DLIOW"),
 
-        encryptToNormal.setString(encryptToNormal.convert());
+            // Mixed case with spaces and punctuation
+            Arguments.of("Hello World!", "Svool Dliow!"), Arguments.of("123 ABC xyz", "123 ZYX cba"),
 
-        assertEquals(expectedText, encryptToNormal.getString());
+            // Palindromes and mixed cases
+            Arguments.of("madam", "nzwzn"), Arguments.of("Palindrome", "Kzormwilnv"),
+
+            // Non-alphabetic characters should remain unchanged
+            Arguments.of("@cipher 123!", "@xrksvi 123!"), Arguments.of("no-change", "ml-xszmtv"),
+
+            // Empty string and single characters
+            Arguments.of("", ""), Arguments.of("A", "Z"), Arguments.of("z", "a"),
+
+            // Numbers and symbols
+            Arguments.of("!@#123", "!@#123"),
+
+            // Full sentence with uppercase, lowercase, symbols, and numbers
+            Arguments.of("Hello World! 123, @cipher abcDEF ZYX 987 madam zzZ Palindrome!", "Svool Dliow! 123, @xrksvi zyxWVU ABC 987 nzwzn aaA Kzormwilnv!"),
+            Arguments.of("Svool Dliow! 123, @xrksvi zyxWVU ABC 987 nzwzn aaA Kzormwilnv!", "Hello World! 123, @cipher abcDEF ZYX 987 madam zzZ Palindrome!"));
     }
 }