RailFenceTest.java

packagecom.thealgorithms.ciphers;

importstaticorg.junit.jupiter.api.Assertions.assertEquals;

importorg.junit.jupiter.api.Test;

publicclassRailFenceTest {

@Test
voidtestEncryption() {
RailFenceCiphercipher = newRailFenceCipher();

Stringinput = "We are discovered! Flee at once";
intrails = 3;
Stringencrypted = cipher.encrypt(input, rails);
assertEquals("Wrivdlaneaedsoee!Fe toc cr e e", encrypted);

StringsingleChar = "A";
intsingleRail = 2;
StringencryptedSingleChar = cipher.encrypt(singleChar, singleRail);
assertEquals("A", encryptedSingleChar);

StringshortString = "Hello";
intmoreRails = 10;
StringencryptedShortString = cipher.encrypt(shortString, moreRails);
assertEquals("Hello", encryptedShortString);

StringinputSingleRail = "Single line";
intsingleRailOnly = 1;
StringencryptedSingleRail = cipher.encrypt(inputSingleRail, singleRailOnly);
assertEquals("Single line", encryptedSingleRail);
 }

@Test
voidtestDecryption() {
RailFenceCiphercipher = newRailFenceCipher();

// Scenario 1: Basic decryption with multiple rails
StringencryptedInput = "Wrivdlaneaedsoee!Fe toc cr e e";
intrails = 3;
Stringdecrypted = cipher.decrypt(encryptedInput, rails);
assertEquals("We are discovered! Flee at once", decrypted);

// Scenario 2: Single character string decryption
StringencryptedSingleChar = "A";
intsingleRail = 2; // More than 1 rail
StringdecryptedSingleChar = cipher.decrypt(encryptedSingleChar, singleRail);
assertEquals("A", decryptedSingleChar);

// Scenario 3: String length less than the number of rails
StringencryptedShortString = "Hello";
intmoreRails = 10; // More rails than characters
StringdecryptedShortString = cipher.decrypt(encryptedShortString, moreRails);
assertEquals("Hello", decryptedShortString);

// Scenario 4: Single rail decryption (output should be the same as input)
StringencryptedSingleRail = "Single line";
intsingleRailOnly = 1;
StringdecryptedSingleRail = cipher.decrypt(encryptedSingleRail, singleRailOnly);
assertEquals("Single line", decryptedSingleRail);
 }
}