express-catch-rejected-promises.js

// this wraps an async express route handler function into a try-catch
// it returns a new function which handles failures gracefully 
// by sending a JSON encoded message and a HTTP 500 (internal server error) status code
function expressTryCatchWrapper(requestHandler) {
    return async function (req, resp, next) {
        try {
            await requestHandler(req, resp, next)
        } catch (ex) {
            console.error(`expressTryCatch ERROR ${req.url}`, ex)
            if (resp.headersSent) {
                console.log(`**** HEADERS SENT ****`)
                return
            }
          
            return resp.status(500).json({
                message,
                info: ex.toString()
            })
        }
    }
}
export { expressTryCatchWrapper }

//async await

//wrapping route handlers
const getPostContactInfo =async (req, res) => {
    try{
        const data = await databaseFetch()
        return resp.status(200).send({data})
        
    }
    catch(e){
       return resp.status(500).json({
                message,
                info: ex.toString()
            })        
    }
}

const getPostContactInfo = expressTryCatchWrapper(async (req, res) => {

    if(Math.random()<0.5){
      res.json({ email, phone })
    }else{
      throw new Error(`Bummer!`)
    }
    
})

app.get('/', getPostContactInfo )