[node] Stack locals

[smeubank]

Problem Statement

Node js does not capture stack locals similar to a few other server side SDKs

Stack-locals → Some SDKs (Python and PHP) will pick up variable values within the stacktrace. These can be scrubbed, or this behavior can be disabled altogether if necessary.

comment from an unrelated NextJs issue: #6321 (comment)

Could this be easily applied to remix, next, and any other fromworks depending on Node?

Solution Brainstorm

There are possible concerns in Node that this would create some overhead (if it is possible at all)

If it was to be implemented could it be controlled by some user flag?

[smeubank]

summarizing some internal discussions on this issue in story form:

@lforst found out

• Seems it actually should be possible to access debugger data at runtime with Node Inspector API
  then @AbhiPrasad said
• users essentially must turn on debug mode
• Since you can disable inspect in node
  then @kamilogorek did
• local tests confirm it works on some level

[AbhiPrasad]

@kamilogorek

[kamilogorek]

@kamilogorek

[AbhiPrasad]

[smeubank]

[smeubank]

https://github.com/kamilogorek/sentry-node-local-variables

@kamilogorek example

Refactored everything so its easier to understand

https://github.com/kamilogorek/sentry-node-local-variables/blob/master/vars.js

[timfish]

Oh this is really nice!

[timfish]

How do you want this adding? Keep it as an integration?

Should I do some testing to see how long this suspends the event loop to determine if this can be enabled by default?

[AbhiPrasad]

Keep it as an integration?

Yes please!

Should I do some testing to see how long this suspends the event loop to determine if this can be enabled by default?

This would be great, but we can also put this off. We can make this opt-in to start, and default it in v8. So we do it the following way.

1. release the integration, gate it with a top level option
2. update sentry docs to enable this option by default (so they copy past Sentry.init with the option set to true)
3. set the option to be true by default in v8

[github-actions]

This issue has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Status: Backlog or Status: In Progress, I will leave it alone ... forever!

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"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀

[therealarkin]

Question - is there anything we need to do/tell the customer to do on the issues details page to enable this if this is not enabled?

[smeubank]

Question - is there anything we need to do/tell the customer to do on the issues details page to enable this if this is not enabled?

@therealarkin user need to configure like this

covered here blog post and SDK docs here

not sure how to detect if they are missing, in terms of the event payload