monorepo: Normalize exception values in error handling

[ScottyPoi]

Implements suggestion in issue #3687

Replacing this pattern:

try {
...
} catch (e: any) {
   ...
}

with

try {
...
} catch (e) {
   if (!(e instanceof Error) {
         e = new Error(e)
       }
  ...
}

Changes to tsconfig and eslint.config:

The following rules were disabled

• @typescript-eslint/no-redeclare: ['Error']
• no-ex-assign
• useUnknownInCatchVariables

[holgerd77]

I don't think we have to set this down, when reading on no-redeclare we are not redeclaring anyhting but only reassiging, which is totally norma, right?

I did a quick test re-adding the original rule setup and runnpm run lint from root, still seems to work.

[holgerd77]

Ok, this rule no-ex-assign seems out of question (as discussed)

[holgerd77]

Ah, this needs to be the otheway around: we want to have unknown there, atm this now goes to any:

So and this is the version of when removing the new assignment with e still being any:

So no underlying of e.message (what we would want. any is just saying: use whatever you want, I do not care! 🙂

With unknown is the more strict version - indicating that for e we just don't (and can't) know the type.

Ah, just seeing that a plain use in new Error() is then not directly possible. 🤔

But for any we still have typed as any. Also not optimal:

Hmm. Let me give this some thought, input welcome from the team.

[holgerd77]

Will give this a "WIP" label again to indicate that we need to re-think this to some extend and this needs some continued work, so that this won't get merged accidentally.

We nevertheless should already think and reason about this.

[holgerd77]

So this has settled to the following (in discussion with @jochem-brouwer):

1. Make it unknown with useUnknownInCatchVariables ts config variable (which resembles reality)
2. Check for Error instance, then do normal error handling
3. Otherwise re-throw

So that we basically do an adopted version from this StackOverflow answer, so like:

try {
  throw new Error('foo');
} catch (err) { // unknown not necessary since we set the flag
  if (err instanceof Error) {
    // Do what we did before with the error
  } else {
    // Rethrow the error
  }
}

Jochem, could you do a final confirmation (or correction) here?

@ScottyPoi if you can go along + Jochem confirms, can you update the PR? Thanks! 🙏 🙂

[jochem-brouwer]

Yes this is correct! Note, thus set useUnknownInCatchVariables to true!