Core: Catch and do nothing to avoid triggering unhandled exception problems

[tmeasday]

Issue: #20161

What I did

Put an extra empty .catch() in to avoid the issue.

Explanation

Try running this code:

async function errorFunction() {
  throw new Error('error')
}

async function go() {
  try {
    const r = errorFunction()
    //  r.then(() => { });
    await r;
  } catch (err) {
    console.log('caught error');
    await new Promise((r) => setTimeout(r, 10));
    console.log('done');
  }
}

go();

As written it will exit 0 and log:

caught error
done

If you comment the .then() block, it will exit 1 and log:

caught error
/Users/tom/GitHub/storybookjs/storybook/sandbox/nextjs-default-js/test.js:2
  throw new Error('error')
        ^

Error: error
    at errorFunction (/Users/tom/GitHub/storybookjs/storybook/sandbox/nextjs-default-js/test.js:2:9)
    at go (/Users/tom/GitHub/storybookjs/storybook/sandbox/nextjs-default-js/test.js:7:15)
    at Object.<anonymous> (/Users/tom/GitHub/storybookjs/storybook/sandbox/nextjs-default-js/test.js:17:1)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:17:47

If you put a .catch() in before the .then() it will do the first behaviour.

I suppose node has a heuristic for whether exceptions are being handled that is wrong here. We could also (and maybe should) add a process.on('unhandledException') to deal with this.

How to test

Run a sandbox (not with --ci) and put a incorrect import in a file.

[shilman]

Crazy stuff 🤯

Thanks so much for getting to the bottom of this @tmeasday -- you're a hero!