Sveltekit Post Request how to return a Response Object with non blocking database access?

Question

I'm trying to send a POST request to a +server.js endpoint that saves the data to the database without blocking my code from execution

/** @type {import('./$types').RequestHandler} */
export async function POST({ request }) {

    request.json()
        .then((data) => {
            console.log("data: ", data);
            getConnection()
                .then((conn) => {
                    let sql = "INSERT INTO accounts (username, password, socialMediaPlatform, accountLink) VALUES (?, ?, ?, ?)";
                    let result = conn.query(sql, [data.username, data.password, data.socialMediaPlatform, data.accountLink]);
                    conn.release();

                    return new Response(JSON.stringify(result), {
                        status: 200,
                    });
            })
            .catch((err) => {
                return new Response(JSON.stringify({error: err}), {
                    status: 400,
                });
            });
        })
        .catch((err) => {
            return new Response(JSON.stringify({error: err}), {
                status: 400,
            });
        });
}

However I'm getting this error:

Invalid response from route /api/account: handler should return a Response object

But it somehow works and writes the data to the database.

Bonusquestion: I'm also getting this errormessage from vscode when hovering over the POST function Shouldn't this be typescript specific? And shouldn't the error only come if

Answer 1

You are not actually returning anything, as all the return statements are inside functions. You have to add a return at the very start (return request.json()...) and before getConnection or use await instead of chaining (which I would recommend).

TS can check JS as well, there are the flags allowJs and checkJs.