Catch express bodyParser error

Question

I want to catch the error from the bodyParser() middleware when I send a json object and it is invalid because I want to send a custom response instead of a generic 400 erro

Answer 1

(bodyParser, req, res) => new Promise((resolve, reject) => {
    try {
        bodyParser(req, res, err => {
            if (err instanceof Error) {
                reject(err);
            } else {
                resolve();
            }
        });
    } catch (e) {
        reject(e);
    }
})

Bullet-proof. Future-aware. WTFPL-Licensed. And also useful w/ async/await.