nodejs gmail api not supporting promises

Question

Google recommends using promises, but its code examples do not, and I'm struggling to make the gmail api work with promises when I modify the code from the online docs.

All I've changed are the lines below, but I get an error

VM677:5 Uncaught TypeError: gmail.users.messages.list(...).then is not a function

gmail.users.messages.list({
    auth: auth,
    userId: 'me',
    labelIds: 'Label_14'
// }, function(err, response) {
//     if (err) {
//         console.log('The API returned an error: ' + err);
//         return;
//     }
//     console.log(response);
})
.then(response => {
    console.log("success", response);
})

Most of the examples of SO use promises so I think it should be possible but I can't see what the problem is. Would really welcome some help

Answer 1

The googleapis module does not support promises.

Consider using util.promisify if you want to use promises with this module.

var list = util.promisify(gmail.users.messages.list);

list({
    auth: auth,
    userId: 'me',
    labelIds: 'Label_14'
})
.then(...);