javascript how to write a function that handles dynamic method chaining

Question

So lets say I have the following method

api.post('users')
        .set(key,value);
        .send(data)
        .expect(201)

I was curious in javascript how I could set up a function to dynamically call/chain .set on the first method based on the number of keys in an object? So if I had the object foo = {a: 1, b:2 , c:2}

the function would behave like the following

 api.post('users')
            .set(a,1)
            .set(b,2)
            .set(c,3)
            .send(data)
            .expect(201)

Answer 1

The function can simply call .set in a loop:

function setMultiple(api, values) {
    for (var key in values) {
        if (values.hasOwnProperty(key)) {
            api = api.set(key, values[key]));
        }
    }
    return api;
}