Separate Events API from Logs API

[martinkuba]

This change separates the Events API into a separate package. This has been discussed in this specs issue, and prototyped in Java here.

This makes it possible to have instrumentation code depend only on the Events API without having to take in the whole Logs API as a dependency. The Logs API can remain reserved for log appenders only (not exposed in instrumentations or user code).

Follow-up work:

• implement a Logs SDK (that has no knowledge of the Events API)
• implement an Events SDK that uses a Logs API behind the scenes

[codecov]

Codecov Report

Merging #3550 (946db02) into main (ae3b428) will decrease coverage by 1.05%.
The diff coverage is 97.36%.

❗ Current head 946db02 differs from pull request most recent head 97569a7. Consider uploading reports for the commit 97569a7 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3550      +/-   ##
==========================================
- Coverage   93.90%   92.86%   -1.05%     
==========================================
  Files         255      138     -117     
  Lines        7763     3264    -4499     
  Branches     1613      673     -940     
==========================================
- Hits         7290     3031    -4259     
+ Misses        473      233     -240     

Impacted Files	Coverage Δ
...ackages/api-events/src/platform/node/globalThis.ts	0.00% <0.00%> (ø)
...mental/packages/api-events/src/NoopEventEmitter.ts	100.00% <100.00%> (ø)
...ackages/api-events/src/NoopEventEmitterProvider.ts	100.00% <100.00%> (ø)
experimental/packages/api-events/src/api/events.ts	100.00% <100.00%> (ø)
...l/packages/api-events/src/internal/global-utils.ts	100.00% <100.00%> (ø)
experimental/packages/api-logs/src/NoopLogger.ts	100.00% <100.00%> (ø)
api/src/platform/node/globalThis.ts	0.00% <0.00%> (-100.00%)	⬇️
...s/opentelemetry-core/src/platform/node/sdk-info.ts	0.00% <0.00%> (-100.00%)	⬇️
...opentelemetry-core/src/platform/node/globalThis.ts	0.00% <0.00%> (-100.00%)	⬇️
...pentelemetry-core/src/platform/node/performance.ts	0.00% <0.00%> (-100.00%)	⬇️
... and 130 more

[pichlermarc]

Looks great, thank you for taking the time to split these apart 🙂
Just a few nits + one question 🙂

[scheler]

Some clarifications on event domain.

[martinkuba]

@dyladan The failing unit tests don't seem to be related to this PR.

[dyladan]

@dyladan The failing unit tests don't seem to be related to this PR.

they are not related. its the flaky test mentioned in SIG

[legendecas]

The specification still lists the event-api as part of the logs specification. Does it worth creating a dedicated package for event-api?

Update: sorry, missed the links. Otherwise LGTM.

Naming bikeshed: EventEmitter is a Node.js built-in API. It would be confusing in JavaScript if the API is named as EventEmitter but is not a Node.js EventEmitter instance.

[martinkuba]

@legendecas I brought up the EventEmitter name topic in today's SIG meeting, and there is probably a preference from others to choose a different name as well. The reason I chose EventEmitter was to follow the prototype in Java, and also to get away from the previous EventLogger name in order to make it clear that it is not a "logger" (to distinguish it from the Log API).

I am open to suggestions about a different name. And I would also ask that this discussion does not prevent this PR from being merged. We would like to continue work on the Log and Events SDKs, which are currently blocked by this change. If ok with you, I would suggest that we merge this PR with the EventEmitter name, and continue the discussion in a separate issue (which will probably need to make it into the spec).