Nexjs + SWR: API resolved without sending a response for /api/projects/<slug>, this may result in stalled requests - axios

Question

Since on first render I was not able to get the router.query I am passing the params from getServerSideProps as follows:
export async function getServerSideProps(context) {
return {
props: { params: context.params },
};
}
Then in the function am trying to do the API call but am getting the API stalled error
API resolved without sending a response for
/api/projects/nichole_robel23, this may result in stalled requests.
This is my code:
export default function Project({ params }) {
const { slug } = params;
let [projectData, setProjectData] = useState([]);
let [loading, setLoading] = useState(true);
const { data } = useSWR('http://localhost:3000/api/projects/' + slug);
useEffect(() => {
if (data) {
setProjectData(data.data.project);
setLoading(false);
}
}, [data]);
......
I have global SWRCofig as follows
<SWRConfig value={{ fetcher: (url) => axios(url).then(r => r.data) }}>
<Layout>
<Component {...pageProps} />
</Layout>
</SWRConfig>
Any way to solve the problem?

Answer 1

You are missing your fetcher–the function that accepts the key of SWR and returns the data, so the API is not being called.
You are also not returning a response correctly from the API–this is most likely a case of not waiting for a promise/async to be fulfilled correctly.
CLIENT
const fetcher = (...args) => fetch(...args).then((res) => res.json());
export default function Home({ params }) {
const { slug } = params;
const [projectData, setProjectData] = useState([]);
const [loading, setLoading] = useState(true);
const { data } = useSWR(`http://localhost:3000/api/projects/${slug}`, fetcher);
useEffect(() => {
if (data) {
setProjectData(data);
setLoading(false);
}
}, [data]);
API
const getData = () => {
return new Promise((resolve, reject) => {
// simulate delay
setTimeout(() => {
return resolve([{ name: 'luke' }, { name: 'darth' }]);
}, 2000);
});
}
export default async (req, res) => {
// below will result in: API resolved without sending a response for /api/projects/vader, this may result in stalled requests
// getData()
// .then((data) => {
// res.status(200).json(data);
// });
// better
const data = await getData();
res.status(200).json(data);
}