Add breadcrumbs filter option

[skeggse]

Right now, I'm filtering out some analytics xhrs from the breadcrumbs by using the dataCallback parameter:

function filterCrumbs(crumb) {
 // For example.
 return crumb.category !== 'xhr' || !crumb.data.url.startsWith('https://example.com');
}

Raven.config({
 // ...
 dataCallback(payload) {
 try {
 if (!payload.breadcrumbs) return payload;
 payload.breadcrumbs.values = payload.breadcrumbs.values.filter(filterCrumbs);
 } catch (err) {
 // Don't block logging on xhr filtering.
 }
 return payload;
 }
});

It would be convenient if there were a filterCrumbs option, or something like it - payload.breadcrumbs.values isn't explicitly documented, and as such it feels brittle.

[benvinegar]

Hey Mixmax gang – breadcrumb configuration is on my radar, starting with just flat-out turning them on/off. This makes sense too.

[benvinegar]

Just a heads up that 3.5.0 now collects 100 breadcrumbs by default (you can reduce by changing maxBreadcrumbs). We also have breadcrumb filtering coming to the Sentry UI soon. I'd see if those changes will make this tolerable for you.

[elicwhite]

We make a bunch of requests to an analytics endpoint as well. We also want to filter those out but want to do that before they count against the 100 breadcrumbs. I'm planning on opening a PR that adds another callback for filtering breadcrumbs.