Using setTimeout on promise chain

To keep the promise chain going, you can’t use setTimeout() the way you did because you aren’t returning a promise from the .then() handler – you’re returning it from the setTimeout() callback which does you no good.

Instead, you can make a simple little delay function like this:

function delay(t, v) {
    return new Promise(resolve => setTimeout(resolve, t, v));
}

And, then use it like this:

getLinks('links.txt').then(function(links){
    let all_links = (JSON.parse(links));
    globalObj=all_links;

    return getLinks(globalObj["one"]+".txt");

}).then(function(topic){
    writeToBody(topic);
    // return a promise here that will be chained to prior promise
    return delay(1000).then(function() {
        return getLinks(globalObj["two"]+".txt");
    });
});

Here you’re returning a promise from the .then() handler and thus it is chained appropriately.

You can also add a delay method to the Promise object and then directly use a .delay(x) method on your promises like this:

function delay(t, v) {
    return new Promise(resolve => setTimeout(resolve, t, v));
}

Promise.prototype.delay = function(t) {
    return this.then(function(v) {
        return delay(t, v);
    });
}


Promise.resolve("hello").delay(500).then(function(v) {
    console.log(v);
});