Tseam Account JS Fundamentals

function tseamAccount(arr) {
    let account = arr.shift().split(' ');

    for (let line of arr) {
        let tokens = line.split(' ');
        let command = tokens[0];
        let gameName = tokens[1];

        switch (command) {
            case "Install":
                if (!account.includes(gameName)) {
                    account.push(gameName);
                }
                break;
            case "Uninstall":
                if (account.includes(gameName)) {
                    let index = account.indexOf(gameName);
                    account.splice(index, 1);
                }
                break;
            case "Update":
                if (account.includes(gameName)) {
                    let game = account.indexOf(gameName);
                    account.splice(game, 1);
                    account.push(gameName);
                }
                break;
            case "Expansion":
                let expansionParts = tokens[1];
                let parts = expansionParts.split('-');
                let game = parts[0];
                let expansion = parts[1];
                let unit = game + ':' + expansion;
                if (account.includes(game)) {
                    let index = account.indexOf(game);

                    account.splice(index + 1, 0, unit);
                }
                break;
            case "Play!":
                break;
        }
    }
    console.log(account.join(' '));
}