Add unit tests for SimpleSubCipher (TheAlgorithms#3688)

Author: AlexandreVelloso

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

@@ -19,8 +19,8 @@ public class SimpleSubCipher {
  * @param cipherSmall
  * @return Encrypted message
  */
- public static String encode(String message, String cipherSmall) {
- String encoded = "";
+ public String encode(String message, String cipherSmall) {
+ StringBuilder encoded = new StringBuilder();
 
  // This map is used to encode
  Map<Character, Character> cipherMap = new HashMap<>();
@@ -39,13 +39,13 @@ public static String encode(String message, String cipherSmall) {
 
  for (int i = 0; i < message.length(); i++) {
  if (Character.isAlphabetic(message.charAt(i))) {
- encoded += cipherMap.get(message.charAt(i));
+ encoded.append(cipherMap.get(message.charAt(i)));
  } else {
- encoded += message.charAt(i);
+ encoded.append(message.charAt(i));
  }
  }
 
- return encoded;
+ return encoded.toString();
  }
 
  /**
@@ -56,10 +56,10 @@ public static String encode(String message, String cipherSmall) {
  * @param cipherSmall
  * @return message
  */
- public static String decode(String encryptedMessage, String cipherSmall) {
- String decoded = "";
+ public String decode(String encryptedMessage, String cipherSmall) {
+ StringBuilder decoded = new StringBuilder();
 
- Map<Character, Character> cipherMap = new HashMap<Character, Character>();
+ Map<Character, Character> cipherMap = new HashMap<>();
 
  char beginSmallLetter = 'a';
  char beginCapitalLetter = 'A';
@@ -74,21 +74,13 @@ public static String decode(String encryptedMessage, String cipherSmall) {
 
  for (int i = 0; i < encryptedMessage.length(); i++) {
  if (Character.isAlphabetic(encryptedMessage.charAt(i))) {
- decoded += cipherMap.get(encryptedMessage.charAt(i));
+ decoded.append(cipherMap.get(encryptedMessage.charAt(i)));
  } else {
- decoded += encryptedMessage.charAt(i);
+ decoded.append(encryptedMessage.charAt(i));
  }
  }
 
- return decoded;
+ return decoded.toString();
  }
 
- public static void main(String[] args) {
- String a = encode(
- "defend the east wall of the castle",
- "phqgiumeaylnofdxjkrcvstzwb"
- );
- String b = decode(a, "phqgiumeaylnofdxjkrcvstzwb");
- System.out.println(b);
- }
 }

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

@@ -0,0 +1,37 @@
+package com.thealgorithms.ciphers;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+class SimpleSubCipherTest {
+
+ SimpleSubCipher simpleSubCipher = new SimpleSubCipher();
+
+ @Test
+ void simpleSubCipherEncryptTest() {
+ // given
+ String text = "defend the east wall of the castle";
+ String cipherSmall = "phqgiumeaylnofdxjkrcvstzwb";
+
+ // when
+ String cipherText = simpleSubCipher.encode(text, cipherSmall);
+
+ // then
+ assertEquals("giuifg cei iprc tpnn du cei qprcni", cipherText);
+ }
+
+ @Test
+ void simpleSubCipherDecryptTest() {
+ // given
+ String encryptedText = "giuifg cei iprc tpnn du cei qprcni";
+ String cipherSmall = "phqgiumeaylnofdxjkrcvstzwb";
+
+ // when
+ String decryptedText = simpleSubCipher.decode(encryptedText, cipherSmall);
+
+ // then
+ assertEquals("defend the east wall of the castle", decryptedText);
+ }
+
+}