CODEWITHSUNDEEP
typescriptpromise
ColinKennedy
ColinKennedy

Reputation: 998

typescript unhandledRejection Promise

I call an external process using typescript, like this:

import { execSync } from 'child_process'
execSync('/my/executable/here')

But the executable is has an error in it, which is causing execSync to fail. Is there a way to catch the error (as a string) and print it or assign it to variable?

I tried doing this but the code still keeps saying "unhandledRejection Promise"

let promise = new Promise((resolve, reject) => {
    execSync('/my/executable/here')
})
promise.then(result => console.log('CALL RAN'))
promise.catch(error => console.log('FOUND ERROR'))

The error that I get looks like this:

2019-11-26T00:17:23.060 ERROR (pid:36622) [server] - unhandledRejection  Promise {
  <rejected> Error: Command failed: /my/executable/here

Upvotes: 0

Views: 1112

Answers (1)

Martin
Martin

Reputation: 1419

You need to catch the error and then resolve/reject as appropriate.

e.g.

// Try to use const where possible
const promise = new Promise((resolve, reject) => {
  try {  
    execSync('/my/executable/here');
    resolve();
  } catch(e) {
    reject(e);
  }
})

// Chain the promise handlers
promise
  .then(result => console.log('CALL RAN'))
  .catch(error => console.log('FOUND ERROR'));

Upvotes: 2

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