feat: APM updates

[kamilogorek]

This PR provides the new @sentry/apm package with a new Tracing integration.
The Tracing integration creates Transactions for pageloads as well as navigation changes. Additionally, it will add the sentry-trace header so if used together with an apm enabled server SDK of Sentry (Node, Python) you will get the full trace.

We also hook into global XHR & fetch calls and create spans out of it that will be attached to the transaction.

[getsentry-bot]

	Messages
📖	✅ TSLint passed
📖	@sentry/browser bundle gzip'ed minified size: (ES5: 16.5586 kB) (ES6: 15.5605 kB)

Generated by 🚫 dangerJS against 073920f

[kamilogorek]

cc @mitsuhiko for last commit

[HazAT]

Let's call this childSpan instead of newSpan

[ajacques]

What's the long-term plan around APM in Sentry? Is there overlap with or a plan to integrate with OpenCensus/OpenTelemetry? OpenCensus just released a prototypeJavaScript implementation and I'd love to avoid having to integrate 2-3 different tracing systems.

[kamilogorek]

@ajacques we're still in early PoC phase so there's not much I can say for certain, but we do have OC/OT in mind while working on it :)

[HazAT]

TODO: (!) Circular dependency: ../hub/src/hub.ts -> ../hub/src/span.ts -> ../hub/src/hub.ts

[Bessonov]

Hi guys, I found the blog post about Sentry APM. As I understand, Sentry wants to support not only error logging, but also tracing, right? Is there any plan to support "normal" Logging for better analysability of errors or do we still need tools like ELK?

[kamilogorek]

Remember that isNaN('')isNaN([])isNaN(null)isNaN(true)isNaN(false) will also report false. You can wrap the input in parseInt to make it better, or use:

typeof TransactionActivity.options.tracesSampleRate !== 'number'

[kamilogorek]

sucky :(

[dashed]

@HazAT@kamilogorek Can the span status also be part of the trace/span context?

[dashed]

Damn. So fast.