Cant send a message using Gmail API in browser

Question

I am trying to send email using Gmail API in my browser app. My function looks like:

function sendMessage(recepient, message, done) {
    var base64EncodedEmail = '';
    var request = gmail.users.messages.send({
        to: recepient,
        userId: 'me',
        resource: {
            raw: base64EncodedEmail
        }
    });
    request.execute(done);
}

I am getting the following:

'raw' RFC822 payload message string or uploading message via /upload/* URL required

What am I doing wrong here?

Answer 1

Figured out ... thanks to Google REST API - message in an RFC 2822 formatted and base64url encoded string. The new function is

function sendMessage(recepient, subject, message, done) {
    var base64EncodedEmail = btoa(`From: me\r\nTo: ${recepient}\r\nSubject: ${subject}\r\n\r\n${message}`)
        .replace(/[\/\+]/g, '_')
        .replace(/=+$/, '');
    var request = gmail.users.messages.send({
        userId: 'me',
        resource: { raw: base64EncodedEmail }
    });
    request.execute(done);
}