module.evaluateSync() inside isolate swallows error

[Strate]

Hello.

I am trying to implement something like importScripts api, but with modules. I realized, that calling module.evaluateSync() inside isolate swallows module-level error, but that error caught outside of isolate.

Self-contained example:

const ivm = require("isolated-vm")

const isolate = new ivm.Isolate();
const context = isolate.createContextSync();

try {
  context.evalClosureSync(`
    const isolate = $0;
    const context = $1;
    const log = (...args) => $2.applySync(null, args);
    const module = isolate.compileModuleSync("throw new Error('Error from module')");
    module.instantiateSync(context, () => {});
    try {
      module.evaluateSync();
    } catch (e) {
      log("Error caught inside", e)
      throw e
    }
    log("This should not be invoked")
  `, [
    isolate,
    context,
    new ivm.Reference((...args) => console.log(...args))
  ])
} catch (e) {
  console.log('Caught error outside:', e)
}

I expected output:

Error caught inside: Error from module
Caught error outside: Error from module

But received output:

This should not be invoked
Caught error outside: Error: Error from module

Could you please help me with this? Is it a bug, or I am doing something wrong?

Thanks a lot for this awesome library!

[laverdet]

v8 unfortunately changed the way modules worked after I wrote all this. I can't recommend the *Sync class of functions when working with modules, since they return promises internally. Instead, structure your code as async/await with the async methods.

[Strate]

@laverdet thank you for quick response!

Actually, I am trying to implement lazy-loading of imported modules, something like this

import * as module1 from "./module1" // this one would resolve to Proxy

function fn() {
  return module_1.member; // accessing to proxy should sync load (via applySyncPromise) "./module1" content, create & eval module, return exported members
}

Actually, everything working fine, except module-level errors.

Looks like that task is not possible at all, if you could not recommend *Sync methods?