raven - capture breadcrumb on failed request

[kumavis]

Fixes #1009

If there is an issue performing the request (not an error response from the server), we don't get any data about what failed, only a TypeError: Failed to Fetch with no trace or hint of what was being fetched.

With this change, we capture a breadcrumb indicating that the fetch failed, then re-throw the error.

If there is no additional catch in the chain, this will result in an unhandled promise rejection with the original unhelpful error message: TypeError: Failed to Fetch.

Question: can you set a log level on a type: 'http' breadcrumb? will this be rendered correctly in Sentry?

[kumavis]

i dont understand the lint error

.catch is a syntax error

[kamilogorek]

@kumavis https://github.com/kumavis/raven-js/blob/d36dea71f683feea03a625507563b3cac912e521/src/raven.js#L2058-L2061

[kamilogorek]

Question: can you set a log level on a type: 'http' breadcrumb? will this be rendered correctly in Sentry?

Yes, you should be able to do this just fine

[kumavis]

@kamilogorek that seems like gratuitous coding around the linter, instead of removing an unnecessary lint rule or just adding a flag to ignore the lint rule in this case

[kumavis]

and yet this is what eslint --fix produces
whatever, let me commit that

[kumavis]

ECMAScript version 3 compatible style, avoiding dot notation for reserved word properties.

'catch' is a reserved word in ECMAScript 3, IE8 & 9 require this written in brackets e.g. this['catch'].bind() rather than the dot notation.

hmm, TIL

[kumavis]

@kamilogorek ready to go if it looks good to you

[kamilogorek]

I was trying to find this explanation and post it here. Thanks :)

[kumavis]

@kamilogorek thanks/ looking forward to getting this live to help diagnose some of our sentry reports 😸

[kamilogorek]

@kumavis I'll release a new version once this fix gets merged - #1302
Hopefully on Monday morning (as I try not to release on Fridays if its not a major issue) :)

[kamilogorek]

@kumavis released as 3.24.2

[victorpavlenko]

@kumavis
@kamilogorek

Still, doesn't work

TypeError: Failed to fetch
/ in _promiseRejectionHandler
No additional details are available for this frame.

v: raven-js : 3.24.2

[kumavis]

@Xurma2 note that this doesnt re-add the stack, its just supposed to add a breadcrumb

@kamilogorek doesnt seem like its actually adding the breadcrumb, but not sure why

relevant code is now here

sentry-javascript/packages/raven-js/src/raven.js

Lines 1486 to 1496 in a01b4ee

	['catch'](function(err) {
	// if there is an error performing the request
	self.captureBreadcrumb({
	type: 'http',
	category: 'fetch',
	data: fetchData,
	level: 'error'
	});
	throw err;
	});

[kamilogorek]

@kumavis would you mind giving new v4 SDK a try? We are only supporting security/major issues in old raven-js for quite some time now. In new SDK it's handled here though -

sentry-javascript/packages/browser/src/integrations/breadcrumbs.ts

Line 260 in 56e7648

throw error;

[kumavis]

@kamilogorek i dont know why i didnt see it before -- but I do see the Failed to fetch breadcrumbs now