ci(llmobs): re-work deepEqualWithMockValues to use node:assert

[sabrenner]

What does this PR do?

Changes the LLM Observability deepEqualWithMockValues to use node:assert instead of mocha expect. Also in doing this, refactor the logic to do bi-directional assertions. The reason this is a bit complicated is because we sometimes want to assert structure with "mock" values in certain places. This is a common practice in our LLM integration testing, especially for related metadata, as shape of objects change often, and we just want to assert that something exists (MOCK_ANY), or exists with a certain type (MOCK_STRING, MOCK_OBJECT, etc.).

Motivation

Fix the test utility to properly assert and not rely on mocha utilities.

Follow-up items

There are a few follow-up items to re-enable tests that previously did not fail (incorrectly):

• Fix the ai integration for correct tool argument tagging for v5 of the library
• Undefined messages for Cohere models with aws-sdk bedrockruntime
• No output roles for cached token tests for aws-sdk bedrock runtime
• A langchain test seems flaky due to a VCR incompatibility. the test does pass occasionally, so i don't believe it to be an issue with the test. i would like to do a follow-up investigation into how the underlying operation of that test (batched llm calls) is interacting with the testagent's vcr capabilities
• A couple OpenAI errors where input metadata is not recorded correctly when the underlying openai call fails
• Skipped an evaluation metric test which I will quick follow up on re-enabling. Just needs a handler in our local testagent server and an additional method in our llm observability test utilities

Additionally, there are some other tests that need to be updated in a similar cleanup initiative:

• The rest of the LLM Observability SDK tests still use expect, and should be changed to use node:assert
• The existing "integration" tests should probably be migrated to actual integration tests

[github-actions]

Overall package size

Self size: 13.15 MB
Deduped: 115.95 MB
No deduping: 118.16 MB

Dependency sizes

| name | version | self size | total size | |------|---------|-----------|------------| | @datadog/libdatadog | 0.7.0 | 35.02 MB | 35.02 MB | | @datadog/native-appsec | 10.3.0 | 20.73 MB | 20.74 MB | | @datadog/native-iast-taint-tracking | 4.0.0 | 11.72 MB | 11.73 MB | | @datadog/pprof | 5.11.1 | 9.96 MB | 10.34 MB | | @opentelemetry/core | 1.30.1 | 908.66 kB | 7.16 MB | | protobufjs | 7.5.4 | 2.95 MB | 5.82 MB | | @datadog/wasm-js-rewriter | 4.0.1 | 2.85 MB | 3.58 MB | | @opentelemetry/resources | 1.9.1 | 306.54 kB | 1.74 MB | | @datadog/native-metrics | 3.1.1 | 1.02 MB | 1.43 MB | | @opentelemetry/api-logs | 0.207.0 | 201.39 kB | 1.42 MB | | @opentelemetry/api | 1.9.0 | 1.22 MB | 1.22 MB | | jsonpath-plus | 10.3.0 | 617.18 kB | 1.08 MB | | import-in-the-middle | 1.15.0 | 127.66 kB | 856.24 kB | | lru-cache | 10.4.3 | 804.3 kB | 804.3 kB | | @datadog/openfeature-node-server | 0.1.0-preview.12 | 95.11 kB | 401.68 kB | | opentracing | 0.14.7 | 194.81 kB | 194.81 kB | | source-map | 0.7.6 | 185.63 kB | 185.63 kB | | pprof-format | 2.2.1 | 163.06 kB | 163.06 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 | 7.0.5 | 63.38 kB | 63.38 kB | | istanbul-lib-coverage | 3.2.2 | 34.37 kB | 34.37 kB | | rfdc | 1.4.1 | 27.15 kB | 27.15 kB | | dc-polyfill | 0.1.10 | 26.73 kB | 26.73 kB | | @isaacs/ttlcache | 1.4.1 | 25.2 kB | 25.2 kB | | tlhunter-sorted-set | 0.1.0 | 24.94 kB | 24.94 kB | | shell-quote | 1.8.3 | 23.74 kB | 23.74 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 | | mutexify | 1.4.0 | 5.71 kB | 8.74 kB | | path-to-regexp | 0.1.12 | 6.6 kB | 6.6 kB | | module-details-from-path | 1.0.4 | 3.96 kB | 3.96 kB | | escape-string-regexp | 5.0.0 | 3.66 kB | 3.66 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 83.78%. Comparing base (b874514) to head (ef719cb).
⚠️ Report is 12 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6709      +/-   ##
==========================================
- Coverage   83.89%   83.78%   -0.11%     
==========================================
  Files         500      506       +6     
  Lines       21117    21256     +139     
==========================================
+ Hits        17716    17810      +94     
- Misses       3401     3446      +45     

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[pr-commenter]

Benchmarks

Benchmark execution time: 2025-10-30 20:23:04

Comparing candidate commit ef719cb in PR branch sabrenner/rework-llmobs-test-assertions with baseline commit b874514 in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 1607 metrics, 63 unstable metrics.

[BridgeAR]

This is mostly LGTM. I do have a few questions for understanding and the assertions are all type insensitive (doing the loose comparison) now. Is that intentional? Could we use strict comparison instead?