Refactor caesarCipher tests for better coverage

src/algorithms/cryptography/caesar-cipher/__test__/caesarCipher.test.js

@@ -1,40 +1,101 @@
+(Sem assunto)
+teo machado<teobaldomachado22@gmail.com>
+Você
 import { caesarCipherEncrypt, caesarCipherDecrypt } from '../caesarCipher';
 
 describe('caesarCipher', () => {
-  it('should not change a string with zero shift', () => {
-    expect(caesarCipherEncrypt('abcd', 0)).toBe('abcd');
-    expect(caesarCipherDecrypt('abcd', 0)).toBe('abcd');
-  });
+describe('caesarCipherEncrypt', () => {
+it.each([
+{ input: 'abcd', shift: 0, expected: 'abcd' },
+{ input: 'abcde', shift: 1, expected: 'bcdef' },
+{ input: 'abcde', shift: 3, expected: 'defgh' },
+{ input: 'xyz', shift: 1, expected: 'yza' },
+{ input: 'z', shift: 1, expected: 'a' },
+{ input: 'ABCDE', shift: 3, expected: 'defgh' },
+{ input: '', shift: 3, expected: '' },
+{ input: 'ab2cde', shift: 3, expected: 'de2fgh' },
+{ input: 'Hello, World!', shift: 3, expected: 'khoor, zruog!' },
+])(
+'encrypts "
 
-  it('should cipher a string with different shifts', () => {
-    expect(caesarCipherEncrypt('abcde', 3)).toBe('defgh');
-    expect(caesarCipherDecrypt('defgh', 3)).toBe('abcde');
+shift',
+({ input, shift, expected }) => {
+expect(caesarCipherEncrypt(input, shift)).toBe(expected);
+},
+);
 
-    expect(caesarCipherEncrypt('abcde', 1)).toBe('bcdef');
-    expect(caesarCipherDecrypt('bcdef', 1)).toBe('abcde');
+it('should preserve non-alphabetic characters', () => {
+expect(caesarCipherEncrypt('123 !@#', 5)).toBe('123 !@#');
+});
 
-    expect(caesarCipherEncrypt('xyz', 1)).toBe('yza');
-    expect(caesarCipherDecrypt('yza', 1)).toBe('xyz');
-  });
+it('should handle shifts greater than the alphabet length', () => {
+expect(caesarCipherEncrypt('abc', 27)).toBe('bcd');
+});
 
-  it('should be case insensitive', () => {
-    expect(caesarCipherEncrypt('ABCDE', 3)).toBe('defgh');
-  });
+it('should handle a negative shift', () => {
+expect(caesarCipherEncrypt('abc', -1)).toBe('zab');
+});
+});
 
-  it('should correctly handle an empty strings', () => {
-    expect(caesarCipherEncrypt('', 3)).toBe('');
-  });
+describe('caesarCipherDecrypt', () => {
+it.each([
+{ input: 'abcd', shift: 0, expected: 'abcd' },
+{ input: 'bcdef', shift: 1, expected: 'abcde' },
+{ input: 'defgh', shift: 3, expected: 'abcde' },
+{ input: 'yza', shift: 1, expected: 'xyz' },
+{ input: 'a', shift: 1, expected: 'z' },
+{ input: '', shift: 3, expected: '' },
+{ input: 'de2fgh', shift: 3, expected: 'ab2cde' },
+{
+input: 'khoor, zruog!',
+shift: 3,
+expected: 'hello, world!',
+},
+])(
+'decrypts "
 
-  it('should not cipher unknown chars', () => {
-    expect(caesarCipherEncrypt('ab2cde', 3)).toBe('de2fgh');
-    expect(caesarCipherDecrypt('de2fgh', 3)).toBe('ab2cde');
-  });
+shift',
+({ input, shift, expected }) => {
+expect(caesarCipherDecrypt(input, shift)).toBe(expected);
+},
+);
 
-  it('should encrypt and decrypt full phrases', () => {
-    expect(caesarCipherEncrypt('THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG', 23))
-      .toBe('qeb nrfzh yoltk clu grjmp lsbo qeb ixwv ald');
+it('should handle shifts greater than the alphabet length', () => {
+expect(caesarCipherDecrypt('bcd', 27)).toBe('abc');
+});
 
-    expect(caesarCipherDecrypt('qeb nrfzh yoltk clu grjmp lsbo qeb ixwv ald', 23))
-      .toBe('the quick brown fox jumps over the lazy dog');
-  });
+it('should handle a negative shift', () => {
+expect(caesarCipherDecrypt('zab', -1)).toBe('abc');
+});
+});
+
+describe('encryption and decryption round trip', () => {
+it.each([
+{ input: 'hello world', shift: 3 },
+{ input: 'the quick brown fox', shift: 23 },
+{ input: 'abc xyz', shift: 26 },
+{ input: 'Text with 123 symbols!', shift: 7 },
+{ input: '', shift: 10 },
+])(
+'should recover the original text for shift $shift',
+({ input, shift }) => {
+const encrypted = caesarCipherEncrypt(input, shift);
+const decrypted = caesarCipherDecrypt(encrypted, shift);
+
+expect(decrypted).toBe(input.toLowerCase());
+},
+);
+});
+
+describe('full phrase', () => {
+it('should encrypt and decrypt the pangram correctly', () => {
+const original = 'THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG';
+const encrypted = 'qeb nrfzh yoltk clu grjmp lsbo qeb ixwv ald';
+
+expect(caesarCipherEncrypt(original, 23)).toBe(encrypted);
+expect(caesarCipherDecrypt(encrypted, 23)).toBe(
+'the quick brown fox jumps over the lazy dog',
+);
+});
 });
+});