add new baggage APIs which act on currently active baggage

[ida613]

What does this PR do?

Provides users with a set of global functions which act on the currently active baggage of implicitly propagated context

Motivation

From the baggage RFC:

Generally speaking, the Baggage API should be exposed on the Context object or class on APM SDKs where the context itself is exposed. On SDKs where context is implicit, the Baggage API can be exposed through static/global functions that act on the currently active baggage.

Added return statements because

If any language implements baggage as an immutable object or data structure (as defined in the OpenTelemetry Baggage API specification), the functions above that modify baggage (set and remove) will need to return the new (modified) baggage object. However, if baggage is mutable and modified in place, those functions don't need to return a value.

Plugin Checklist

• Unit tests.
• TypeScript definitions.
• TypeScript tests.
• API documentation.
• CircleCI jobs/workflows.
• Plugin is exported.

Additional Notes

[github-actions]

Overall package size

Self size: 9.33 MB
Deduped: 102.57 MB
No deduping: 103.09 MB

Dependency sizes

| name | version | self size | total size | |------|---------|-----------|------------| | @datadog/libdatadog | 0.5.1 | 29.73 MB | 29.73 MB | | @datadog/native-appsec | 8.5.2 | 19.33 MB | 19.34 MB | | @datadog/native-iast-taint-tracking | 3.3.1 | 13.99 MB | 13.99 MB | | @datadog/pprof | 5.7.1 | 9.51 MB | 9.88 MB | | @opentelemetry/core | 1.30.1 | 908.66 kB | 7.16 MB | | protobufjs | 7.4.0 | 2.77 MB | 5.42 MB | | @datadog/wasm-js-rewriter | 4.0.0 | 2.85 MB | 3.58 MB | | @datadog/native-metrics | 3.1.1 | 1.02 MB | 1.43 MB | | @opentelemetry/api | 1.8.0 | 1.21 MB | 1.21 MB | | import-in-the-middle | 1.13.1 | 117.64 kB | 839.26 kB | | source-map | 0.7.4 | 226 kB | 226 kB | | opentracing | 0.14.7 | 194.81 kB | 194.81 kB | | lru-cache | 7.18.3 | 133.92 kB | 133.92 kB | | pprof-format | 2.1.0 | 111.69 kB | 111.69 kB | | @datadog/sketches-js | 2.1.1 | 109.9 kB | 109.9 kB | | lodash.sortby | 4.7.0 | 75.76 kB | 75.76 kB | | ignore | 5.3.2 | 53.63 kB | 53.63 kB | | istanbul-lib-coverage | 3.2.0 | 29.34 kB | 29.34 kB | | rfdc | 1.4.1 | 27.15 kB | 27.15 kB | | @isaacs/ttlcache | 1.4.1 | 25.2 kB | 25.2 kB | | dc-polyfill | 0.1.8 | 25.08 kB | 25.08 kB | | tlhunter-sorted-set | 0.1.0 | 24.94 kB | 24.94 kB | | shell-quote | 1.8.2 | 23.54 kB | 23.54 kB | | limiter | 1.1.5 | 23.17 kB | 23.17 kB | | retry | 0.13.1 | 18.85 kB | 18.85 kB | | semifies | 1.0.0 | 15.84 kB | 15.84 kB | | jest-docblock | 29.7.0 | 8.99 kB | 12.76 kB | | crypto-randomuuid | 1.0.0 | 11.18 kB | 11.18 kB | | ttl-set | 1.0.0 | 4.61 kB | 9.69 kB | | path-to-regexp | 0.1.12 | 6.6 kB | 6.6 kB | | koalas | 1.0.2 | 6.47 kB | 6.47 kB | | module-details-from-path | 1.0.3 | 4.47 kB | 4.47 kB |

_{🤖 This report was automatically generated by heaviest-objects-in-the-universe}

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.37%. Comparing base (28eaa41) to head (433b9e2).
Report is 104 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5365      +/-   ##
==========================================
- Coverage   79.47%   79.37%   -0.10%     
==========================================
  Files         509      515       +6     
  Lines       22811    23437     +626     
==========================================
+ Hits        18128    18603     +475     
- Misses       4683     4834     +151     

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[datadog-datadog-prod-us1]

Datadog Report

Branch report: ida613/global-baggage
Commit report: 6ac3235
Test service: dd-trace-js-integration-tests

✅ 0 Failed, 930 Passed, 0 Skipped, 14m 54.99s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-04-14 22:48:56

Comparing candidate commit 433b9e2 in PR branch ida613/global-baggage with baseline commit 28eaa41 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 915 metrics, 18 unstable metrics.

[BridgeAR]

The transport itself seems fine, I just don't see how this is integrated and exposed to users. That is something that still needs to be addressed :)

[ida613]

The transport itself seems fine, I just don't see how this is integrated and exposed to users. That is something that still needs to be addressed :)

Should I update our api documentation? Are there other ways we can expose global functions to users?

[ida613]

@BridgeAR Hey Ruben, I reached out to Rachel, who implemented context-based public baggage APIs for golang, and there is really nothing left to do except maybe for adding the APIs to the public doc. Are you able to give this PR a go? Thank you :)

[ida613]

@BridgeAR sorry about misunderstanding you before! I have added the APIs to NoopProxy to make them accessible to the public. Please let me know if this solution is fine and I'll update the test :)

[BridgeAR]

Thanks for exposing the API now!
While it would work that way, it should not be on the no op proxy class. The name is an indicator for no operation, so all methods on that class should just do nothing. Instead, the API should probably be exposed on the main Tracer proxy.
Can you please also add tests that actually use the API as an integration test and also add documentation for it?

[ida613]

@BridgeAR thank you for your review Ruben! :) This is awkward, technically baggage is separate from tracing and does not require tracing to be enabled to work

[BridgeAR]

@ida613 that is fair! I feel I am actually not the right person to suggest where to add the functionality in that case. I just know that it should not be the NoopProxy.

@rochdev do you have an opinion about that?

[bengl]

The methods should be added to the proxy in dd-trace/src/proxy.js. No-op versions of this should be added to the NoopTracer proxy (i.e. the one currently in this file).

[rochdev]

This is awkward, technically baggage is separate from tracing and does not require tracing to be enabled to work

Unfortunately the original design of the library was only a tracer (hence the name dd-trace) and the default export ended up being the tracer itself. This means that anything, whether or not related to tracing, needs to be on the tracer to be exposed. Of course that could be directly on the proxy instead of the underlying tracer, but from a public API perspective they are the effectively the same. The underlying implementation however should indeed not be coupled to tracing.

[ida613]

Made changes as Bryan suggested! Will work on tests now

[ida613]

@BridgeAR @rochdev I've updated the tests. Let me know if there is anything else to update :)

[BridgeAR]

The code is looking good to me!

I believe we still need some documentation for it. Otherwise it would be pretty much "in the wild" :D
I believe our TS definition is pretty much that documentation, if I am not mistaken.

[ida613]

@BridgeAR added the TS definition! let me know if it's good to go :)