Can't catch error from an erroneous uploadDir path with a trycatch block

Support plan

• which support plan is this issue covered by? (e.g. Community, Sponsor, or Enterprise):Community
• is this issue currently blocking your project? (yes/no):no
• is this issue affecting a production system? (yes/no):no

Context

• node version:12.16.1
• module (formidable) version:1.2.2
• environment (e.g. node, browser, native, OS):node
• used with (i.e. popular names of modules):express
• any other relevant information:

What are you trying to achieve or the steps to reproduce?

Can’t catch error from an erroneous uploadDir path with a trycatch block

try{
  const form = formidable({ uploadDir: path.join(__dirname, "/sth-weird") })
}catch(err){
  console.log("err", err)
}

What was the result you got?

events.js:288 throw er; // Unhandled ‘error’ event ^

Error: ENOENT: no such file or directory, open ‘C:\Users\username\Documents\project\server\routers\sth-weird\a.jpg’ Emitted ‘error’ event on WriteStream instance at: at internal/fs/streams.js:320:12 at FSReqCallback.oncomplete (fs.js:154:23) { errno: -4058, code: ‘ENOENT’, syscall: ‘open’, path: ‘C:\Users\username\Documents\project\server\routers\sth-weird\a.jpg’ }

What result did you expect?

Error logged

[ljc-dev]

Thanks for the detailed explanation!!! I’ll try this on my next project. 👍

[tunnckoCore]

There’s no point in using try catch in event driven API. Errors and everything is through events, in case of error on('error') is emitted so.

I don’t see how calling just formidable() will error, it’s just not possible cuz there’s nothing done in the constructor that can produce error. Error can happen some time after the parse is called, in which case it should emit error event and not throw. If you are saying that it’s throwing, than yes it’s a problem and should be handled internally, I agree on that. All this will change with v2/v3 with simplifying the API and codebase a LOT.

Good workaround is to wrap everything in a Promise constructor and then work with promises entirely.

const promise = new Promise((resolve, reject) => {
  const form = formidable();
  form.on('error', reject);
  form.parse(req, (err, files, fields) => 
	err ? reject(err) : resolve({ files, fields})
  )
});

try {
  await promise
} catch (err) {}

which is overkill compared to just using

Yep, definitely.