useCheatCodes react hook

useCheatCodes.ts

/**
 * @author Thomas Kalve <https://github.com/tkalve>
 */
import { useRef, useCallback, useEffect } from "react";

/**
 * Listens to cheat code sequences and triggers a callback when any sequence is entered
 *
 * @param callback - Function to call when any cheat code is entered
 */
export function useCheatCodes(callback: (name: string) => void): void {
  useCheatCode("RG9vbSBHb2QgbW9kZXxpfGR8ZHxxfGQ=", callback);
  useCheatCode("U2ltIENpdHkgMjAwMCBkZWJ1ZyBjaGVhdHxwfHJ8aXxzfGN8aXxsfGx8YQ==", callback);
  useCheatCode("S29uYW1pIGNvZGV8QXJyb3dVcHxBcnJvd1VwfEFycm93RG93bnxBcnJvd0Rvd258QXJyb3dMZWZ0fEFycm93UmlnaHR8QXJyb3dMZWZ0fEFycm93UmlnaHR8YnxhfEVudGVy", callback);
  useCheatCode("TW9ydGFsIEtvbWJhdCBCbG9vZCBjb2RlfGF8YnxhfGN8YXxifGI=", callback);
  useCheatCode("VGhlIFNpbXMgTW9uZXkgY2hlYXR8cnxvfHN8ZXxifHV8ZA==", callback);
}

/**
 * Listens to a single cheat code sequence and triggers a callback when the sequence is entered
 *
 * @param input - Base64 encoded cheat code in format btoa("Name|k|e|y|s")
 * @param callback - Function to call when the cheat code is entered
 */
function useCheatCode(input: string, callback: (name: string) => void): void {
  const parts = atob(input).split("|");
  const name = parts.shift() ?? "";
  const sequence = parts;

  const buffer = useRef<string[]>([]);
  const keySequence = useCallback(
    (event: KeyboardEvent) => {
      if (event.defaultPrevented) return;

      if (event.key === sequence[buffer.current.length]) {
        buffer.current = [...buffer.current, event.key];
      } else {
        buffer.current = [];
      }

      if (buffer.current.length === sequence.length) {
        const bufferString = buffer.current.toString();
        const sequenceString = sequence.toString();

        if (sequenceString === bufferString) {
          //console.trace("Code entered: ", name);
          callback(name);
        }
      }
    },
    [callback, name, sequence]
  );

  useEffect(() => {
    document.addEventListener("keydown", keySequence);
    return () => document.removeEventListener("keydown", keySequence);
  }, [keySequence]);
}

Cheat codes before Base64 encoding:

Doom God mode|i|d|d|q|d
Sim City 2000 debug cheat|p|r|i|s|c|i|l|l|a
Konami code|ArrowUp|ArrowUp|ArrowDown|ArrowDown|ArrowLeft|ArrowRight|ArrowLeft|ArrowRight|b|a|Enter
Mortal Kombat Blood code|a|b|a|c|a|b|b
The Sims Money cheat|r|o|s|e|b|u|d