throw callback error in Promise

[lemures-t]

Hi. Now I need to throw the error, which sometimes occurs in webpack compiler's callback, to terminate the node process.

webpack(webpackConfig, (err, stats) => {
  if (err) throw err
  // ...
})

But UnhandledPromiseRejectionWarning was received, indicating the error thrown from callback was wrapped in promise chain and the node process was not terminated as expected. After debugging, I found the following code triggered the warning.

attachAfterEmitHook(compiler, (compilation, cb) => {
  this.finalizeRelease(compilation).then(() => cb())
});

Error thrown in cb was wrapped in this.finalizeRelease promise chain. Would you mind calling the cb in setTimeout method to throw out the possible error from promise chain, like:

this.finalizeRelease(compilation).then(() => {
  setTimeout(function(){
    cb()
  })
})

many thanks

[jan-auer]

Two thoughts here:

1. In order to end the node process, you could also call process.exit(1).
2. Putting this in a timeout would simply create a globally unhandled exception in Node, which is in no way better than an unhandled promise rejection (except for different console output).

You should probably consider a mechanism other than throwing to end the compilation. Also note that by the time this happens, a release has already been created on Sentry (and thus symbols uploaded), which might be confusing if your process dies afterwards.

[lemures-t]

@jan-auer We have to exit the process since the failure of some other plugins or procedures may cause problems in our web app. But still many thx. I understand what you mean.