CI: run the JavaScript and Elixir SDK unit tests on pull requests #520

Area: .github/workflows/ci.yml, sdks/javascript/sdk, sdks/elixir/sdk

Problem

CI only tests the Python SDK (python-sdk-test, 3.10–3.14 matrix). The other SDKs in sdks/ have test suites that no workflow runs. Searching .github/workflows/ for sdks/javascript, sdks/elixir, mix test, go test, or swift test finds nothing.

A PR can break the JS or Elixir SDK and still pass every check.

Both suites can already run without secrets

JavaScript:

• vitest.config.ts already excludes the benchmark and cloud-version suites (search.test.ts, create_index_versions.test.ts).
• The cloud suites (cloudFallback, customEmbeddings, hotReload, mossClient.imageDataset, mossClientE2e) are gated with describe.skipIf(!HAS_REAL_CLOUD_CREDS), which reads MOSS_TEST_PROJECT_ID / MOSS_TEST_PROJECT_KEY in test/constants.ts.
• helpers.test.ts and mossClient.test.ts run offline.

Elixir:

• test/test_helper.exs has ExUnit.start(exclude: [:integration, :embedding, :session]), so a plain mix test runs only the offline tests.
• The native core (sdks/elixir/bindings, {:moss_core, path: "../bindings"}) uses rustler_precompiled, so CI shouldn't need a Rust toolchain unless a force-build flag is set. Confirm this while implementing.

Proposed solution

Add two jobs to .github/workflows/ci.yml, or a new sdk-tests.yml with paths: filters so they only run when the SDK changes.

javascript-sdk-test

• actions/setup-node with Node 20 and 22, cache-dependency-path: sdks/javascript/sdk/package-lock.json
• npm ci, npm run lint, npx tsc --noEmit, npm test
• Check that the @moss-dev/moss-core native addon installs on ubuntu-latest. The config sets pool: 'forks' because of native-addon issues, so keep that.

elixir-sdk-test

• erlef/setup-beam with an OTP/Elixir pair matching mix.exs
• cache deps and _build
• mix deps.get, mix format --check-formatted, mix compile --warnings-as-errors, mix test

Optional: a separate job that runs the cloud suites only on push to main when MOSS_TEST_PROJECT_ID / MOSS_TEST_PROJECT_KEY secrets exist, following the pattern of NEXT_PUBLIC_MOSS_PROJECT_* in next-js-test.

Acceptance criteria

• A PR that changes sdks/javascript/sdk/** runs lint, type-check, and offline vitest, and fails on a broken test.
• A PR that changes sdks/elixir/sdk/** or sdks/elixir/bindings/** runs mix test (integration/embedding/session tags excluded).
• Neither job needs repository secrets on fork PRs.
• If lint or format checks fail on the current code, the fixes land in the same PR, or those steps start as non-blocking with a follow-up issue.
• CONTRIBUTING.md or each SDK README documents how to run these tests locally.

Overlap check

• Go is out of scope: PR feat(go): add SDK with release-downloaded native bindings #501 already adds .github/workflows/go-sdk-test.yml.
• PR ci: run the packages/* pytest suites #492 only runs the packages/* pytest suites, not sdks/.
• CI: reproducible benchmark harness with tracked results #435 / PR Add CI benchmark suite: latency + recall regression tracking #446 cover benchmark tracking, not unit tests.
• SDK: Rust bindings #410/SDK: Kotlin / Android bindings #411/SDK: Ruby client for Moss #430/SDK: .NET client for Moss #431/SDK: React Native and Expo module #432 are for new SDKs. This issue only adds CI for SDKs already on main.