Missing stacktrace in renderer process when using Node.js API integration

[clemp6r]

• Review the documentation: https://docs.sentry.io/platforms/javascript/electron/
• Search for existing issues: https://github.com/getsentry/sentry-electron/issues
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Versions + Platform

• SDK version - @sentry/electron@v2.4.0
• Electron version - electron@v11.0.4
• Platform - macOS

Description

When capturing a exception thrown by the Node integration in the renderer process, the reported stacktrace is empty.

Sample code to reproduce:

  const exec = promisify(childProcess.exec);
  const command = `commandThatFails`;
  let stdout: string;
  try {
    const response = await exec(command);
    stdout = response.stdout;
  } catch (error) {
    console.log('got error', error);
    stdout = error.stdout;
    if (!stdout) {
      Sentry.captureException(error);
    }
  }

The console prints the following (we can see here the value of error.stack):

got error Error: Command failed: commandThatFails
/bin/sh: commandThatFails: command not found

    at ChildProcess.exithandler (child_process.js:312)
    at ChildProcess.emit (events.js:315)
    at maybeClose (internal/child_process.js:1021)
    at Socket.<anonymous> (internal/child_process.js:443)
    at Socket.emit (events.js:315)
    at Pipe.<anonymous> (net.js:674)

The error is correctly reported when calling Sentry.captureException(error) but in the Sentry web interface the stacktrace is empty. Only the first two lines appear:

Command failed: commandThatFails
/bin/sh: commandThatFails: command not found

It seems the Sentry client tries to parse the stack as a Chrome stack, but as the error comes from the Node integration, the format does not match and all frames are skipped.

[timfish]

Currently @sentry/node is used in the main process and @sentry/browser is used in the renderers.

If we can detect the difference between a Chrome exception and a nodejs exception, we might be able to call into @sentry/node in the browser. The main obstacle is the fact that @sentry/node currently makes use of nodejs functionality and this would need to be abstracted out.

I haven't looked into this for years, but I'm pretty sure Electron in its default configuration rethrows nodejs exceptions in the browser context. I think you might be able to stop that by subscribing to error events on process.

[clemp6r]

I'm pretty sure Electron in its default configuration rethrows nodejs exceptions in the browser context

Indeed, that's why I get a node-like stack in my renderer process, instead of a chrome-like stack object.

I think you might be able to stop that by subscribing to error events on process.

I don't understand, can you elaborate on this? What are we supposed to stop?

[timfish]

You don't want to catch each exception twice. Once from nodejs, and once from Electron forwarding to Chrome.

I seem to remember that subscribing to the nodejs error events disables the re-throwing in the Chrome context.

[clemp6r]

You don't want to catch each exception twice

That's not what is happening. See my sample code: Node APIs are called from the renderer, and then an error is thrown and is caught a few lines below, in the renderer.

[timfish]

Sorry, I haven't been very clear there!

I understand your issue and it is caused by the fact that @sentry/node is not used in the renderer.

I'm saying that to fix your issue, @sentry/electron needs to be modified to use @sentry/node in the renderer and we need to ensure that exceptions are not caught twice.

[clemp6r]

Besides, I looked again at my sample stacktrace and it seems there is nothing interesting into, it apart technical framework frames. No function from my application appear. I may have to create new Error objects if I want to have a good stracktrace. Or it is Sentry's responsiblity?

  try {
    const response = await exec(command);
  } catch (error) {
    console.log('got error', error);
    stdout = error.stdout;
    if (!stdout) {
      const wrappedError = new Error('Unable to run command: ' + error);
      Sentry.captureException(wrappedError);
    }
    ...