我可以从服务工作者注册中得到实际错误吗？

Question

For example, if I have a code like this:

script.js :

// ...
try {
  const serviceWorkerRegistration = await navigator.serviceWorker.register('/serviceWorker.js');
  await serviceWorkerRegistration.update();
  // ...
} catch (e) {
  console.error(e); // here I want to get an actual error
}
// ...

serviceWorker.js :

// ...
ddd; // the line with an error
// ...

Can I get the actual error ( Uncaught ReferenceError: ddd is not defined ) in my script.js instead of TypeError: Failed to update a ServiceWorker for scope (...) ServiceWorker script evaluation failed ? My code is more complex and I see in my Sentry project that some browsers can't parse the service worker script, but I want to understand the reason for that case. Also, I added Sentry client to my service worker, but anyway, an error can be thrown before it's registered.

Answer 1

If there are some browsers that can't parse your code then it really just comes down to transpiling your code to a previous version of javascript. However, if these are tests that you are running then you have a development version that wrap your code in eval .

Just to be clear:

Uncaught ReferenceError: ddd is not defined

Is a runtime error. It shouldn't be thrown while the engine is parsing your script. However, if you have something like:

let [test] = [ddd]

You will most likely get a syntax error if your engine doesn't understand ES6 destructuring (even if ddd doesn't exist).

This:

ddd

Can be caught within the service worker script like this

self.onerror = e => console.error(e);
ddd;

But if it fails at parsing like this... then it won't work:

self.onerror = e => console.error(e);
if(

However, if you wrap it in an eval :

self.onerror = e => console.error(e);
eval('if(');

Then this work (as eval parsing happens on runtime).