NodeJS / request promise : the promise is resolved automatically - node.js

Question

I use the request-promise node module as following :
let rp = require('request-promise');
I have the following promises chain :
getData().then( data => {
return getUser(data);
})
.then( data => {
return getProfiles(data);
}).then( data => {
updateAddresses(data);
});
The updateAddresses is as following :
function updateAddresses(data){
var promises = data.map( (aProfile) => {
var options = {url:'http://example.com', method:'POST'};
return rp(options);
});
// Promise.all(promises).then(...);
}
So I'm preparing a promise (request-promise) for each element of the array.
The problem is that those promises are firing even when I remove Promise.all !
How is that possible ? How can I make the promise not firing ?
Regards.

Answer 1

Your updateAddresses is not returning anything to call then() on and you aren't waiting on what would be coming out of updateAddress.
function updateAddresses(data){
var promises = data.map( (aProfile) => {
var options = {url:'http://example.com', method:'POST'};
return rp(options);
});
//Return something to then()
return Promise.all(promises).then(...);
}
Then wait on it:
getData().then( data => {
return getUser(data);
})
.then( data => {
return getProfiles(data);
}).then( data => {
return updateAddresses(data);
}).then(e => somethingelse);
Per your requirement to store the mapped address Objects:
function updateAddresses(data) {
return data.map((aProfile) => {
return {
url: 'http://example.com',
method: 'POST'
}
});
}
getData()
.then(data => getUser(data))
.then(data => getProfiles(data))
.then((data) => {
let addressOptions = updateAddresses(data);
/*
* You now have an Array of Objects of the form:
* {
* url: "",
* method: "",
* }
*/
return Promise.resolve(addressOptions);
})
.then(addressOptions => Promise.all(addressOptions.map(address => rp(address))))
.then((arrayOfResolvedData) => {
/*
* arrayOfResolvedData is an Array of data per whatever rp() returns
* probably Response Objects
*/
console.log(arrayOfResolvedData);
})

Answer 2

You could do what zero298 suggested in his edit.
the main problem is that you map your data to an actual promise, rather than something that is ready to execute a promise,
compare
Let promises = Options.map(option => execute(option))
Promise.all(promises)
With
Let promiseGenerators =Options.map(option => () => execute(option))
Promise.all(promiseGenerators.map(generator => generator())
The second you call the function that will return the promise, it will start doing it. That's where the problem was, because you called rp(options) too soon.