handle UnhandledPromiseRejection

catch-promise

/**
Ref: https://jonasjancarik.medium.com/handling-those-unhandled-promise-rejections-when-using-javascript-async-await-and-ifee-5bac52a0b29f
Placement of catch BEFORE and AFTER then: https://stackoverflow.com/questions/42013104/placement-of-catch-before-and-after-then

*/

// 1. Work

(async()=>{   
    return  Promise.reject("a").catch((_error) =>{})  
    // Promise { <state>: "fulfilled", <value>: undefined }
})()


(async()=>{   
    try{
        return await Promise.reject("a")
    }catch(_error){}
    // Promise { <state>: "fulfilled", <value>: undefined }
})()


// 2.NOT work variation

(async()=>{   
    return  Promise.reject("a").catch()  
    // Promise { <state>: "rejected", <reason>: "a" }
    // Uncaught (in promise) a
})()


(async()=>{   
    try{
        return  Promise.reject("a")
    }catch(_error){}
// Promise { <state>: "rejected", <reason>: "a" }
// Uncaught (in promise) a    
})()