Add Junit tests for ColumnarTranspositionCipher.java

DIRECTORY.md

@@ -641,6 +641,7 @@
             * [AutokeyTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/AutokeyTest.java)
             * [BlowfishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BlowfishTest.java)
             * [CaesarTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/CaesarTest.java)
+            * [ColumnarTranspositionCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/ColumnarTranspositionCipherTest.java)
             * [DESTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/DESTest.java)
             * [HillCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/HillCipherTest.java)
             * [PlayfairTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PlayfairTest.java)

src/main/java/com/thealgorithms/ciphers/ColumnarTranspositionCipher.java

@@ -184,24 +184,4 @@ private static void abecedariumBuilder(int value) {
         }
         abecedarium = t.toString();
     }
-
-    private static void showTable() {
-        for (Object[] table1 : table) {
-            for (Object item : table1) {
-                System.out.print(item + " ");
-            }
-            System.out.println();
-        }
-    }
-
-    public static void main(String[] args) {
-        String keywordForExample = "asd215";
-        String wordBeingEncrypted = "This is a test of the Columnar Transposition Cipher";
-        System.out.println("### Example of Columnar Transposition Cipher ###\n");
-        System.out.println("Word being encryped ->>> " + wordBeingEncrypted);
-        System.out.println("Word encrypted ->>> " + ColumnarTranspositionCipher.encrpyter(wordBeingEncrypted, keywordForExample));
-        System.out.println("Word decryped ->>> " + ColumnarTranspositionCipher.decrypter());
-        System.out.println("\n### Encrypted Table ###");
-        showTable();
-    }
 }

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

@@ -0,0 +1,47 @@
+package com.thealgorithms.ciphers;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class ColumnarTranspositionCipherTest {
+    private String keyword;
+    private String plaintext;
+
+    @BeforeEach
+    public void setUp() {
+        keyword = "keyword";
+        plaintext = "This is a test message for Columnar Transposition Cipher";
+    }
+
+    @Test
+    public void testEncryption() {
+        String encryptedText = ColumnarTranspositionCipher.encrpyter(plaintext, keyword);
+        assertNotNull(encryptedText, "The encrypted text should not be null.");
+        assertFalse(encryptedText.isEmpty(), "The encrypted text should not be empty.");
+        // Check if the encrypted text is different from the plaintext
+        assertNotEquals(plaintext, encryptedText, "The encrypted text should be different from the plaintext.");
+    }
+
+    @Test
+    public void testDecryption() {
+        String encryptedText = ColumnarTranspositionCipher.encrpyter(plaintext, keyword);
+        String decryptedText = ColumnarTranspositionCipher.decrypter();
+
+        assertEquals(plaintext.replaceAll(" ", ""), decryptedText.replaceAll(" ", ""), "The decrypted text should match the original plaintext, ignoring spaces.");
+        assertEquals(encryptedText, ColumnarTranspositionCipher.encrpyter(plaintext, keyword), "The encrypted text should be the same when encrypted again.");
+    }
+
+    @Test
+    public void testLongPlainText() {
+        String longText = "This is a significantly longer piece of text to test the encryption and decryption capabilities of the Columnar Transposition Cipher. It should handle long strings gracefully.";
+        String encryptedText = ColumnarTranspositionCipher.encrpyter(longText, keyword);
+        String decryptedText = ColumnarTranspositionCipher.decrypter();
+        assertEquals(longText.replaceAll(" ", ""), decryptedText.replaceAll(" ", ""), "The decrypted text should match the original long plaintext, ignoring spaces.");
+        assertEquals(encryptedText, ColumnarTranspositionCipher.encrpyter(longText, keyword), "The encrypted text should be the same when encrypted again.");
+    }
+}