Hello Caesar!

You are tasked with sending a secret message to Caesar. The way Caesar encodes message is using a Caesar cipher with a shift of three (A -> D, B -> E, Z -> C), so when your program is deciphered with a shift of three (meaning a shift of 23 is applied to it) your program should print the secret message “Hello, Caesar!”.

However, as a red herring your program should print “Hello, World!” with any other shift amount.

Judge

(async function*(context: Context): Challenge {
  const cipher = (str: string, n: number) => {
  const lower = 'abcdefghijklmnopqrstuvwxyz';
  const upper = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
  
  return str.replace(/[a-zA-Z]/g, char => {
  	if (lower.includes(char)) {
    	return lower[(lower.indexOf(char) + n) % 26]
    }
    if (upper.includes(char)) {
    	return upper[(upper.indexOf(char) + n) % 26]
    }
    
    return char;
  })
}
  const originalContext = context.code;
  for (let i = 0; i < 25; i++) {
    context.code = cipher(originalContext, i);
    if (i == 23) { // special non red herring case
      yield (await context.run()).assertEquals("Hello, Caesar!").setName("Secret message");
    } else {
      yield (await context.run()).assertEquals("Hello, World!").setName("Variant " + i)
    }
  }
  return context.noFailures();
})

Example Code

[]["\146\151\154\164\145\162"]["\143\157\156\163\164\162\165\143\164\157\162"]("\162\145\164\165\162\156\40\145\166\141\154")()('\143\157\156\163\157\154\145\56\154\157\147\50\42a\42\40\75\75\40\42\170\42\40\77\40\42\110\145\154\154\157\54\40\103\141\145\163\141\162\41\42\40\72\40\42\110\145\154\154\157\54\40\127\157\162\154\144\41\42\51')