Directly expose noop exporters for spans and logs.

[breedx-splk]

Right now, there's a silly workaround for users that want to disable exporters -- they can simply use SpanExporter.composite(emptyList()) to get the NoOpSpanExporter.INSTANCE implementation. Sure, this is an implementation detail, but its also pretty obvious that when you composite nothing you get nothing. And that just reads clunky.

Since we already have these NoOp implementations, let's just expose them more directly. The implementation is still completely internal, and yes, this does very slightly increase the api surface area, but I think it's within reason and should be an improvement over the composite hack.

Why not metrics? Welp, we don't have an existing NoOpMetricExporter. I'm not entirely sure why, but it might be due to the spec requiring the NoOp API implementation for metrics? 🤷🏻

[breedx-splk]

Additional context: We have an Android user/contributor who wants to turn off spans and metrics and only ever export logs. Right now, there isn't a great way to do that through our high-level DSL...so while I was looking into how we might one day implement this, I came across this little gap.

[jack-berg]

Add for MetricExporter as well!

[jack-berg]

Right now, there isn't a great way to do that through our high-level DSL...so while I was looking into how we might one day implement this, I came across this little gap.

Declarative config

[breedx-splk]

Add for MetricExporter as well!

In the PR description I had written this:

Why not metrics? Welp, we don't have an existing NoOpMetricExporter. I'm not entirely sure why, but it might be due to the spec requiring the NoOp API implementation for metrics? 🤷🏻

Are you suggesting that I add a NoOpMetricExporter as part of this PR?

[breedx-splk]

Declarative config

Maybe one day, but reading files at startup on Android is a pretty serious no-no.

[jkwatson]

needs japicmp run to get the new API surface exposed

[otelbot]

⚠️ API changes detected — additional maintainer review required

@jack-berg @jkwatson

This PR modifies the public API surface area of the following module(s):

• opentelemetry-sdk-logs
• opentelemetry-sdk-trace

Please review the changes in docs/apidiffs/current_vs_latest/ carefully before approving.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.01%. Comparing base (2f1d950) to head (6ab6e04).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #8435      +/-   ##
============================================
+ Coverage     90.96%   91.01%   +0.04%     
- Complexity     7809     7817       +8     
============================================
  Files           892      892              
  Lines         23702    23720      +18     
  Branches       2361     2364       +3     
============================================
+ Hits          21561    21589      +28     
+ Misses         1420     1409      -11     
- Partials        721      722       +1     

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[jkwatson]

worth adding a simple test for these two new methods?

[jack-berg]

Looks good, but bumping this 😉 #8435 (comment)

[jkwatson]

API changes are a go from me.