async/await IIFE

Question

Would anyone be so kind to assist me if I’m ‘cooking’ async/await a right way?

I attend to return an express response once promise to DB resolves.

router.get('/', (req, res, next) => {
  (async function() {
    try {
      const cases = await db.collections.cases.stats();

      return res.render('index', {
        title: 'Welcome',
        totalDBRecords: cases.count,
      });
    }
    catch (e) {
      console.error(e);
      next(e);
    }
  })();
});

Answer 1

I don't think you need to wrap this in an IFFE. You can simply write the async function as follows:

router.get('/', async (res, req, next) => {
     try {
         const cases = await db.collections.cases.stats();

         res.render('index', {
             title: 'Welcome',
             totalDBRecords: cases.count,
         });
     } catch(err) {
          console.log(err);
          next(err);
     }
});

That should work. I also like the way Wes Bos wraps his functions in an error handler, like so (eliminates having to use try/catch).

const catchErr = (fn) => {
    return function(res, req, next) {
        fn(req, res, next).catch(next);
    }
};    
const home = async (res, req, next) => {
     const cases = await db.collections.cases.stats();
     res.render('index', {
         title: 'Welcome',
         totalDBRecords: cases.count,
     });
};
router.get('/', catchErr(home));