test: Find better ways to assert for integration and e2e tests rather than checking logs

[kakkoyun]

Some ideas

For integration tests:

• https://pkg.go.dev/go.opentelemetry.io/otel/sdk/trace/tracetest
• https://pkg.go.dev/go.opentelemetry.io/otel/sdk/metric/metricdata/metricdatatest

For end-to-end tests:

spawn actual collector and use https://opentelemetry.io/docs/specs/otel/protocol/file-exporter/

---

e2e should verify those spans, now that we support http and aligned with otel semconv. Worth an issue?

Originally posted by @txabman42 in #156 (comment)

[txabman42]

@kakkoyun is this duplicated from #214

We can keep this and close the other one. WDYT?

Find better ways to assert spans and add them to e2e and integration tests

[kakkoyun]

@kakkoyun is this duplicated from #214

We can keep this and close the other one. WDYT?

Find better ways to assert spans and add them to e2e and integration tests

Oh yes, they are the same. Sounds good to me. I'll do it.

[txabman42]

In this case, our e2e and integration tests build and start the services (http client/server, etc.) so it'll be hard to use things like tracetest there. I think the best approach is to do sth similar to what opentelemetry-go-instrumentation has done. Create a small custom server which receives the spans and parse them (code).

I'll give it a try to this approach.