Include original error stack trace for Rollbar when throwing error in block pipeline

[twschiller]

Throw block errors reported to Rollbar needs to include original stack trace. Otherwise for application errors we can't pinpoint what line caused the error

Relevant code:

• http://github.com/pixiebrix/pixiebrix-extension/blob/4cf13fc048c6f3b5eac9248227b324b8b78c3cc3/src/runtime/reducePipeline.ts#L570-L570

Related:

• Error using shared service in blueprint #2966

[fregante]

Indeed, we discussed this before I think:

• RFC: don't log errors if you're going to throw them again #1562 (comment)
• Improve error reporting infrastructure #580 (comment)

I'll re-read your long comment in that last thread as it contains a lot information about a setup that we haven't fully achieved yet.

Related:

Do you think I should work on this so we don't have to worry about serialized errors anymore?

• Error subclasses are lost when deserializing sindresorhus/serialize-error#48

Also:

• Add isErrorObject type guard / function sindresorhus/serialize-error#47
• and maybe Add support for (or document) Error#cause sindresorhus/serialize-error#50

[fregante]

I looked into a few solutions:

• Error#cause is already used by ContextError but it doesn't appear to be followed/displayed by Rollbar
• the make-error-cause module seemed to fit but actually just concatenates the stacks
• AggregateError is a new native error group, but unfortunately the console does not show its "children errors" yet and likely neither does Rollbar
• the aggregate-error module seemed to offer a clean API to merge errors and their stacks, but its stack merger/cleaner isn't optimized outside Node

Here's for example what the result of aggregate-error looks like:

So I can suggest just appending the stack like everyone else seems to be doing, something like:

try {
	throw new Error('Original')
} catch (original) {
	const composed = new Error('New details: ' + original.message)
	composed.stack += '\n' + original.stack
	throw composed;
}

and it results into:

Pros:

• no lost details (including each error Type)
• the last-thrown error message contains all the information

I'll turn this pattern into a helper so we can create such wrappers easily, like:

class ContextError extend WrappedError {
	constructor(message, cause, context) {
		super(message, cause); // Will automatically concatenate the message and stacks
		this.context = context;
	}
}

[fregante]

Additionally, for the long term, we'd want Error#cause support in:

• Rollbar (maybe you can open a ticket?)
• getErrorMessage (it would take care of concatenation)
• Add support for (or document) Error#cause sindresorhus/serialize-error#50

[twschiller]

Additionally, for the long term, we'd want Error#cause support in:

• Rollbar (maybe you can open a ticket?)

Opened a ticket with rollbar: rollbar/rollbar.js#1010

A workaround might be to overload the payload transform method? (Which is where we currently re-write the host on the stack track URLS) Although likely the frames from the cause likely don't make their way to the the payload? With your ErrorWithCause though, we might not need to?

[cyrusradfar]

@fregante @twschiller hi, I do Product at Rollbar. I've followed up on the thread in rollbar/rollbar.js

[fregante]

@twschiller great idea! Today I'll see if Rollbar supports the current concatenated stack and if it does I'll move the concatenation logic to that transform. 🎉

[fregante]

Update:

• Rollbar already had (undocumented) support for nested errors using the property nested: (below: b is the cause)

• They just added the same support for cause as well, but it hasn't been shipped yet