1 message.channel.awaitMessages(m => m.author.id == message.author.id,
2                            {max: 1, time: 30000}).then(collected => {
3                                    // only accept messages by the user who sent the command
4                                    // accept only 1 message, and return the promise after 30000ms = 30s
5
6                                    // first (and, in this case, only) message of the collection
7                                    if (collected.first().content.toLowerCase() == 'yes') {
8                                            message.reply('Shutting down...');
9                                            client.destroy();
10                                    }
11
12                                    else
13                                            message.reply('Operation canceled.');      
14                            }).catch(() => {
15                                    message.reply('No answer after 30 seconds, operation canceled.');
16                            });

1
2let filter = m => m.author.id === message.author.id
3    message.channel.send(`Are you sure to delete all data? \`YES\` / \`NO\``).then(() => {
4      message.channel.awaitMessages(filter, {
5          max: 1,
6          time: 30000,
7          errors: ['time']
8        })
9        .then(message => {
10          message = message.first()
11          if (message.content.toUpperCase() == 'YES' || message.content.toUpperCase() == 'Y') {
12            message.channel.send(`Deleted`)
13          } else if (message.content.toUpperCase() == 'NO' || message.content.toUpperCase() == 'N') {
14            message.channel.send(`Terminated`)
15          } else {
16            message.channel.send(`Terminated: Invalid Response`)
17          }
18        })
19        .catch(collected => {
20            message.channel.send('Timeout');
21        });
22    })

1message.channel.awaitMessages(m => m.author.id == message.author.id,
2    { max: 1, time: 30000 }).then(collected => {
3        if (collected.first().content.toLowerCase() == 'yes') {
4            message.reply('Shutting down...');
5            client.destroy();
6        }
7        else
8            message.reply('Operation canceled.');
9    }).catch(() => {
10        message.reply('No answer after 30 seconds, operation canceled.');
11    });