[MLOB-1954] feat(langchain): generically patch embeddings to enable tracing all embeddings calls

[sabrenner]

What does this PR do?

Generically patches LangChain embeddings. We previously hadn't done this because there was no way to patch the prototype for the Embeddings class, since it was an abstract class transpiled from TypeScript, and its abstract functions embedQuery and embedDocuments which we wanted to patch did not end up on the transpiled class.

Instead, we will patch the embeddings exports. Its constructor will now try and shim the embedQuery and embedDocuments functions, as all implementers of Embeddings should implement these methods. While this isn't ideal, it does unblock us from adding provider-specific patches per embedding calls (i.e., we specifically patched @langchain/openai before). Any implementer of Embeddings from @langchain/core/embeddings will be patched.

To go along with this, I added a small test for another embeddings provider (Google Gemini), which revealed some mistakes in logic in grabbing the API key to truncate and tag. One of the downsides of this approach is that we may run into more cases like this (since Embeddings do not have a strictly typed config or properties for config).

Motivation

Reduce noise/line count in the langchain patching for future Embeddings support, just support all instances of Embeddings instead.

Additional Notes

I will try and rework langchain version matrixing for these tests... it's a bit ugly atm.

[github-actions]

Overall package size

Self size: 8.22 MB
Deduped: 94.73 MB
No deduping: 95.29 MB

Dependency sizes

name	version	self size	total size
@datadog/libdatadog	0.2.2	29.27 MB	29.27 MB
@datadog/native-appsec	8.3.0	19.37 MB	19.38 MB
@datadog/native-iast-taint-tracking	3.2.0	13.9 MB	13.91 MB
@datadog/pprof	5.4.1	9.76 MB	10.13 MB
protobufjs	7.2.5	2.77 MB	5.16 MB
@datadog/native-iast-rewriter	2.5.0	2.51 MB	2.65 MB
@opentelemetry/core	1.14.0	872.87 kB	1.47 MB
@datadog/native-metrics	3.0.1	1.06 MB	1.46 MB
@opentelemetry/api	1.8.0	1.21 MB	1.21 MB
import-in-the-middle	1.11.2	112.74 kB	826.22 kB
msgpack-lite	0.1.26	201.16 kB	281.59 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	2.1.0	109.9 kB	109.9 kB
semver	7.6.3	95.82 kB	95.82 kB
lodash.sortby	4.7.0	75.76 kB	75.76 kB
ignore	5.3.1	51.46 kB	51.46 kB
int64-buffer	0.1.10	49.18 kB	49.18 kB
shell-quote	1.8.1	44.96 kB	44.96 kB
istanbul-lib-coverage	3.2.0	29.34 kB	29.34 kB
rfdc	1.3.1	25.21 kB	25.21 kB
@isaacs/ttlcache	1.4.1	25.2 kB	25.2 kB
tlhunter-sorted-set	0.1.0	24.94 kB	24.94 kB
limiter	1.1.5	23.17 kB	23.17 kB
dc-polyfill	0.1.4	23.1 kB	23.1 kB
retry	0.13.1	18.85 kB	18.85 kB
jest-docblock	29.7.0	8.99 kB	12.76 kB
crypto-randomuuid	1.0.0	11.18 kB	11.18 kB
koalas	1.0.2	6.47 kB	6.47 kB
path-to-regexp	0.1.10	6.38 kB	6.38 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}

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-12-05 16:33:00

Comparing candidate commit bcab958 in PR branch sabrenner/langchain-generic-embeddings-patching with baseline commit 865654c in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 263 metrics, 3 unstable metrics.