Activation Keys

function activationKeys(input) {

    let rawKey = input.shift();

    let [command, ...tokens] = input.shift().split('>>>');

    while (command !== 'Generate') {

        if (command === 'Slice') {
            let start = Number(tokens[0]);
            let end = Number(tokens[1]);
            let word = rawKey.slice(start, end);
            rawKey = rawKey.replace(word, '');
            console.log(rawKey);
        } else if (command === 'Flip') {

            let start = Number(tokens[1]);
            let end = Number(tokens[2]);

            if (tokens[0] === 'Upper') {
                let word = rawKey.slice(start, end);
                rawKey = rawKey.split(word).join(word.toLocaleUpperCase());
                console.log(rawKey);
            } else {
                let word = rawKey.slice(start, end);
                rawKey = rawKey.split(word).join(word.toLocaleLowerCase());
                console.log(rawKey);
            }
        } else {

            let cont = rawKey.includes(tokens[0]);
            if (cont) {
                console.log(`${rawKey} contains ${tokens[0]}`);
            } else {
                console.log('Substring not found!');
            }
        }

        [command, ...tokens] = input.shift().split('>>>');
    }

    console.log(`Your activation key is: ${rawKey}`);
}