I'm trying to promisify a function that uses https.get() to get data from an API, so that I can use async await. Here is the example below, it retrieves the data however if I do anything to access the object, such as theData[0] shown below, it will only return Promise { <pending> }
Why am I not able to get asynchronous operation I'm trying for below? Or is there a better way to do this? Basically I'm just trying to make an asynchronous operation with async await, and I need to use https (not fetch, axios, etc).
const myRequest = ((url) => {
return new Promise((resolve, reject) => {
https.get(url, res => {
let data = [];
res.on('data', chunk => {
data.push(chunk);
});
res.on('end', () => {
resolve(JSON.parse(data));
});
}).on('error', err => {
console.log('Error: ', err.message);
});
});
});
async function getApi() {
// write your code here
let url = [url redacted]
await myRequest(url)
.then(data => {
console.log(data[0])
})
.catch(err => {
console.log(err)
});
}
Edit: refactored my helper function with the error handler:
}).on('error', err => {
reject(err)
});
However the promise is still not delivering properly. If I do a simple console.log of the data
async function getApi() {
let url = [url redacted]
const data = await myRequest(url);
console.log(data)
}
It will return Promise { <pending> } and then the JSON:
Promise { <pending> }
{
page: 1,
per_page: 500,
total: 1,
total_pages: 1,
data: [
{
date: '5-January-2000',
open: 5265.09,
high: 5464.35,
low: 5184.48,
close: 5357
}
]
}
I can access that object in the console.log, however, if i try to access anything in this object, it just returns Promise { <pending> }. Such as :
async function getApi() {
let url = [url redacted];
const data = await myRequest(url)
const {high, open} = data.data[0];
return `High: ${high} \n Open: ${open}`
}
First, you need to handle reject as well, or an error will cause a hang. Add reject(err) to your error handler to correctly bubble up the error.
Once you're sure the issue isn't an error, the await usage needs work. await is a tool that takes a promise, and then waits until it resolves to execute synchronously. If you then an awaited promise, you're not getting anything out of your await.
Rewrite the getApi function as:
async function getApi() {
let url = [url redacted]
const data = await myRequest(url);
console.log(data);
}
That will get and log the data, and if the promise is properly rejected, it will bubble that up as an exception.