nesting async/await javascript

Question

Is this valid async/await logic: calling try/catch from within another try/catch?

//within async function...

try { 
    await asyncFunctionFirst();
    } catch (errFirst) {
          try {
              await asyncFunctionSecond();              
          } catch (errSecond) {
              // return errSecond response
          }
      //return errFirst response          
    } 
//return response ok

Wasn't sure if the approach is ok or there is more elegant solution that I'm missing. — t-str-os, Dec 01 '17 at 12:43
No that is the most elegant approach possible (assuming you need to call those methods/perform that logic). The purpose of `async`/`await` is precisely to enable asynchronously logic to be expressed in this fashion. — Aluan Haddad, Dec 01 '17 at 12:43
According to https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/await 'The await operator is used to wait for a Promise. It can only be used inside an async function.' so, I guess it is valid. Have you tested if it runs? — assembler, Dec 01 '17 at 12:44

Bergi · Accepted Answer · 2017-12-01T12:52:40.950

Yes, it's valid syntax. However I would not write it like this. Rather use

try { 
    await asyncFunctionFirst();
    return …; // response ok 
} catch (errFirst) {
    try {
        await asyncFunctionSecond();
        return …; // errFirst response
    } catch (errSecond) {
        return …; // errSecond response
    }
}

(if you would also want to catch exceptions from the … parts - if not, your version is fine, for alternatives see here)

nesting async/await javascript

1 Answers1