LOG {"_U": 0, "_V": 0, "_W": null, "_X": null} inside fetch API - json

Question

I am getting this error when I console data returned from function that fetch data from back end
{"_U": 0, "_V": 0, "_W": null, "_X": null}
here is below the code:
const events_data = [];
function getvals() {
return fetch('http://PCIP:3000/users/timetable')
.then((response) => response.json())
.then((output) => {
return addData(output, events_data);
})
.catch(error => console.log(error))
}
function addData(data, data2) {
data.map((d) => {
data2.push({
title: d.name,
startTime: genTimeBlock(d.day, d.start_time),
endTime: genTimeBlock(d.day, d.end_time),
location: d.location,
extra_descriptions: [d.extra_descriptions],
});
});
}
const data = getvals();
console.log(data); // the error come from here
I have checked answers here but nothing worked for me
fetch API always returns {“_U”: 0, “_V”: 0, “_W”: null, “_X”: null}
How do I access promise callback value outside of the function?

Answer 1

This is because the fetch promise has not return a response yet,
There two way to solve the issue , first you create another async funciton and use it to await for the response
const events_data = [];
async function getvals() {
return fetch('http://PCIP:3000/users/timetable')
.then((response) => response.json())
.then((output) => {
return addData(output, events_data);
})
.catch(error => console.log(error))
}
function addData(data, data2) {
data.map((d) => {
data2.push({
title: d.name,
startTime: genTimeBlock(d.day, d.start_time),
endTime: genTimeBlock(d.day, d.end_time),
location: d.location,
extra_descriptions: [d.extra_descriptions],
});
});
}
async function waitForResponse() {
let resp = await getvals();
return resp;
}
const data = waitForResponse();
console.log(data); // the error come from here
The other way would be using state hooks, passing the return obj to state hook on response.

Answer 2

Function for API call:
export const getApplication = async (URL, headers) => {
let data;
await fetch.get(URL, headers).then(res => data = res.data).catch(err => err);
return data;
}
You can call the API from anywhere after importing it:
getApplication(`your url`, {
headers: {
Authorization: AUTH_TOKEN,
},
}).then(res => console.log(res)).catch(err => console.log(err));