Javascript 来自子异步回调函数的错误句柄

要在主函数的catch块内处理subCallbackFunction回调错误

这是一个错误

 function main(){
    try {
      subCallbackFunction(1,(err,res) =>{
        if(err){
          throw Error(err);
        }          
      })
    } catch (e) {
      /// Want to handle err from here //////
      console.log("Error handle block",e)
    }
}



////// subCallbackFunction ////
async function subCallbackFunction(arg, callback){
    await waitFor(2000);
    //sending error///
    callback("My error")
}
/// Wait Promise //
const waitFor = (ms) => new Promise(r => setTimeout(r, ms));

/// call main function /////
main();

---

只需将主函数设置为异步，并将wait用于嵌套异步函数：

(node:1081) UnhandledPromiseRejectionWarning: Error: My error
(node:1081) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:1081) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

或：

async function main(){
    try {
        await subCallbackFunction(1,(err,res) =>{
            if(err){
                throw Error(err);
            }
        })
    } catch (e) {
        /// Want to handle err from here //////
        console.log("Error handle block",e)
    }
}



////// subCallbackFunction ////
async function subCallbackFunction(arg, callback){
    await waitFor(2000);
    //sending error///
    callback("My error")
}
/// Wait Promise //
const waitFor = (ms) => new Promise(r => setTimeout(r, ms));

/// call main function /////
main();

function main() {
    subCallbackFunction(1, (err, res) => {
        if (err) {
            throw Error(err);
        }
    }).catch(e => {
        console.log("Error handle block", e)
    })
}

////// subCallbackFunction ////
async function subCallbackFunction(arg, callback){
    await waitFor(2000);
    //sending error///
    callback("My error")
}
/// Wait Promise //
const waitFor = (ms) => new Promise(r => setTimeout(r, ms));

/// call main function /////
main();