Edit in JSFiddle

Promise.resolve()
    .then(()=>{
        log('onFulfilled#1 returns thenable');
        return $.post({
            url: '/echo/json/',
            data: {json: JSON.stringify({hello: 'from server'}), delay: 1},
            crossDomain: true
        });
    })
    .then((value)=>{
    	console.log(value);
        log('onFulfilled#2 got value:', JSON.stringify(value));
    });
    
    
function log(...strings){
    let node = document.createElement('div');
    node.innerText = strings.join(' ');
    document.getElementById('log').appendChild(node);
}