Fetch users from GitHub
Create an async function getUsers(names), that gets an array of GitHub user names, fetches them from GitHub and returns an array of GitHub users instead.
The GitHub url with user informaiton is: https://api.github.com/users/USERNAME.
There’s a test example in the sandbox.
Important details:
- There should be one
fetchrequest per user. And requests shouldn’t wait for each other. So that the data arrives as soon as possible. - If a request fails, or if there’s no such user, the function should return
nullin the resulting array.
To fetch a user we need:
fetch('https://api.github.com/users/USERNAME').- If the response has status
200, call.json()to read the JS object.
If a fetch fails, or the response has non-200 status, we just return null in the resulting arrray.
So here’s the code:
async function getUsers(names) {
let jobs = [];
for(let name of names) {
let job = fetch(`https://api.github.com/users/${name}`).then(
successResponse => {
if (successResponse.status != 200) {
return null;
} else {
return successResponse.json();
}
},
failResponse => {
return null;
}
);
jobs.push(job);
}
let results = await Promise.all(jobs);
return results;
}Please note: .then call is attached directly to fetch, so that when we have the response, it doesn’t wait for other fetches, but starts to read .json() immediately.
If we used await Promise.all(names.map(name => fetch(...))), and call .json() on the results, then it would wait for all fetches to respond. By adding .json() directly to each fetch, we ensure that individual fetches start reading data as JSON without waiting for each other.
That’s an example of how low-level Promise API can still be useful even if we mainly use async/await.