dupirefr/dupire.francois+pro@gmail.com [BAEL-2452] Caesar Cipher in Java (#8209)

* Added benchmarking on larger matrices * [BAEL-3452] Added cipher algorithm * [BAEL-3452] Added deciphering * [BAEL-3452] Added break algorithm * [BAEL-3452] Finalizing break algorithm * Revert "Added benchmarking on larger matrices" This reverts commit 4ea87c0aea44bd73be721691a3c427b03854b442.
2019-11-19 08:24:38 +01:00
parent 7d52a39289
commit 6b9f2c74ee
3 changed files with 173 additions and 0 deletions
@@ -0,0 +1,83 @@
+package com.baeldung.algorithms.caesarcipher;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class CaesarCipherUnitTest {
+    private static final String SENTENCE = "he told me i could never teach a llama to drive";
+    private static final String SENTENCE_SHIFTED_THREE = "kh wrog ph l frxog qhyhu whdfk d oodpd wr gulyh";
+    private static final String SENTENCE_SHIFTED_TEN = "ro dyvn wo s myevn xofob dokmr k vvkwk dy nbsfo";
+
+    private CaesarCipher algorithm = new CaesarCipher();
+
+    @Test
+    void givenSentenceAndShiftThree_whenCipher_thenCipheredMessageWithoutOverflow() {
+        String cipheredSentence = algorithm.cipher(SENTENCE, 3);
+
+        assertThat(cipheredSentence)
+          .isEqualTo(SENTENCE_SHIFTED_THREE);
+    }
+
+    @Test
+    void givenSentenceAndShiftTen_whenCipher_thenCipheredMessageWithOverflow() {
+        String cipheredSentence = algorithm.cipher(SENTENCE, 10);
+
+        assertThat(cipheredSentence)
+          .isEqualTo(SENTENCE_SHIFTED_TEN);
+    }
+
+    @Test
+    void givenSentenceAndShiftThirtySix_whenCipher_thenCipheredLikeTenMessageWithOverflow() {
+        String cipheredSentence = algorithm.cipher(SENTENCE, 36);
+
+        assertThat(cipheredSentence)
+          .isEqualTo(SENTENCE_SHIFTED_TEN);
+    }
+
+    @Test
+    void givenSentenceShiftedThreeAndShiftThree_whenDecipher_thenOriginalSentenceWithoutOverflow() {
+        String decipheredSentence = algorithm.decipher(SENTENCE_SHIFTED_THREE, 3);
+
+        assertThat(decipheredSentence)
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedTenAndShiftTen_whenDecipher_thenOriginalSentenceWithOverflow() {
+        String decipheredSentence = algorithm.decipher(SENTENCE_SHIFTED_TEN, 10);
+
+        assertThat(decipheredSentence)
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedTenAndShiftThirtySix_whenDecipher_thenOriginalSentenceWithOverflow() {
+        String decipheredSentence = algorithm.decipher(SENTENCE_SHIFTED_TEN, 36);
+
+        assertThat(decipheredSentence)
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedThree_whenBreakCipher_thenOriginalSentence() {
+        int offset = algorithm.breakCipher(SENTENCE_SHIFTED_THREE);
+
+        assertThat(offset)
+          .isEqualTo(3);
+
+        assertThat(algorithm.decipher(SENTENCE_SHIFTED_THREE, offset))
+          .isEqualTo(SENTENCE);
+    }
+
+    @Test
+    void givenSentenceShiftedTen_whenBreakCipher_thenOriginalSentence() {
+        int offset = algorithm.breakCipher(SENTENCE_SHIFTED_TEN);
+
+        assertThat(offset)
+          .isEqualTo(10);
+
+        assertThat(algorithm.decipher(SENTENCE_SHIFTED_TEN, offset))
+          .isEqualTo(SENTENCE);
+    }
+}