Node: Add OpenFeature server provider by msiebert · Pull Request #255 · mixpanel/mixpanel-node

msiebert · 2026-03-19T18:49:20Z

Summary

Adds openfeature-server-provider/ package implementing OpenFeature server provider
Wraps local or remote flags provider, Symbol sentinel for flag detection
32 tests, all passing

Design

targetingKey not special, STATIC reason, three error codes, onClose no-op

🤖 Generated with Claude Code

hans-lizihan · 2026-04-09T22:41:51Z

hmm we need docs for how to use it? also for this new sub-package, i think it's more appropriate to make it 100% ts native as well, can skip the complicated .d.ts and define all types inline

Implement an OpenFeature provider for the Mixpanel Node SDK as a separate package in openfeature-server-provider/. Wraps either LocalFeatureFlagsProvider or RemoteFeatureFlagsProvider via the shared getVariant() API. Key design decisions: - Uses Symbol sentinel for fallback detection (flag-not-found) - Context set globally via initialize(), per-evaluation context ignored - targetingKey has no special meaning - Handles both sync (local) and async (remote) providers via await - Reason codes: STATIC for success, ERROR for failures - Error codes: PROVIDER_NOT_READY, FLAG_NOT_FOUND, TYPE_MISMATCH - onClose() is a no-op - Returns default value on all errors Includes 32 tests covering all flag types, error cases, async providers, context handling, and edge cases. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Adds PROVIDER_NOT_READY tests for string, number, and object types (boolean was already covered), and SDK exception handling tests verifying that getVariant failures return defaults with error codes. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Merge per-evaluation context on top of init context so callers can override or extend context at each flag evaluation, matching the OpenFeature specification. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- shutdown() now delegates to underlying flags provider - Add areFlagsReady() to LocalFlagsProvider, check before evaluation - Return ErrorCode.GENERAL (not PROVIDER_NOT_READY) for exceptions - Add context value unwrapping with whole-number float→int conversion - Update tests for new error codes and add shutdown/readiness tests Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Extract shared _resolveTypedFlag helper to eliminate ~70 lines of duplicated type-checking across 4 resolve methods. Fix misplaced shutdown() that broke JSDoc association. Remove dead integer truncation code. Fix inconsistent snake_case naming and simplify null checks. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Remove dangerous {value: X} unwrapping heuristic that silently destroyed legitimate context data. Add Date-to-ISO-string conversion. Add await to onClose shutdown. Update TypeScript declarations with optional methods. Add files field to package.json. Add 6 context-building tests. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Required by repo policy — actions must be pinned to full-length commit SHAs rather than version tags. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Track openfeature-server-provider/package-lock.json so npm ci works in CI - Fix prettier formatting in test file Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

areFlagsReady() previously checked flagDefinitions.size > 0, which incorrectly reported "not ready" when the API returned an empty flags array. Now returns a promise that resolves after the first successful fetch, regardless of whether flags were returned. The OpenFeature provider awaits this promise during initialize() instead of using a simple boolean. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

MixpanelProvider.createLocal and createRemote accept a token and config, create the Mixpanel client internally, auto-start polling for local configs, and expose the client via the mixpanel property. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

… flag not found Updates OpenFeature provider reason codes to match the updated spec: - Success: STATIC → TARGETING_MATCH - Flag not found: ERROR → DEFAULT Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

…essages, fix CI - Add JSDoc comments to MixpanelProvider public methods - Bind @openfeature/server-sdk peer dependency to ^1.17.0 - Use npm test with coverage in CI openfeature job - Remove unnecessary article from type mismatch error messages - Fix areFlagsReady return type in index.d.ts (Promise<void>, not boolean) Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

- Move openfeature-server-provider to packages/ as an npm workspace - Convert all source and tests from JavaScript to TypeScript - Add README adapted from the Java OpenFeature provider - Bump main SDK version to 0.21.0 for shutdown method support - Add shutdown() and areFlagsReady() to flag provider type declarations - Add workspace scripts (test:all, build:workspaces) to root package.json - Exclude packages/ from main SDK npm tarball via .npmignore Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

All publishable targets now live under packages/. The root becomes a private workspace orchestrator while the mixpanel npm package ships from packages/mixpanel/ with an explicit files allowlist. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

hans-lizihan · 2026-04-17T19:04:32Z

@@ -0,0 +1,17 @@
+{


i tsconfig and vitest thing should be on root dir

hans-lizihan · 2026-04-17T19:04:58Z

@@ -0,0 +1,2 @@
+dist/


gitignore as well

- Collapse CI into single job using npm run test:all + tsc --build from root; drop working-directory in favor of npm workspaces - Add root tsconfig.json solution file with project references to both packages; both package tsconfigs are now composite - Hoist .gitignore to repo root (adds dist/, *.tsbuildinfo); delete the per-package .gitignore - Bind mixpanel peerDep to ^0.21.0; devDep uses workspace (*) - Add --coverage to both packages' test scripts for parity - Add concise JSDoc to MixpanelProvider public methods Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Both workspace test scripts now emit coverage-final.json; wire it up to codecov-action so PRs get a coverage delta comment. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Move vitest and @vitest/coverage-v8 to root devDependencies so both workspaces share a single version. Also drop typescript from the openfeature package (already in root). Per-package devDeps now contain only package-specific test helpers (nock, proxyquire for mixpanel; @openfeature/core, @openfeature/server-sdk, mixpanel workspace pin for openfeature-server-provider). Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tdumitrescu · 2026-04-29T14:26:43Z

We still need basically this file in the repo root, so that when people visit https://github.com/mixpanel/mixpanel-node they can get instructions for the Node.js SDK right in front of them. Maybe symlink from here (and add a brief section on the directory structure)

tdumitrescu · 2026-04-29T14:32:46Z

-    "test": "vitest",
+    "test": "npm run test --workspaces --if-present",
+    "test:all": "npm run test --workspaces --if-present",
+    "build:workspaces": "npm run build --workspaces --if-present",


make it easier

Suggested change

"build:workspaces": "npm run build --workspaces --if-present",

"build": "npm run build --workspaces --if-present",

"build:workspaces": "npm run build --workspaces --if-present",

(or maybe call these scripts tsc since that's what they really do in practice)

(it also wouldn't be terrible if npm test ran the typechecker too)

tdumitrescu · 2026-04-29T14:34:33Z

+    "node": ">=10.0"
+  },
+  "scripts": {
+    "test": "vitest run --coverage"


let's get a build or tsc script in here too - npx tsc --build will fail if the example in tscheck/ is borked

- Add root readme.md symlink to packages/mixpanel/readme.md so the GitHub landing page shows SDK docs again - Add "Repository structure" section to packages/mixpanel/readme.md - Hoist `build` to root package.json; have `npm test` run tsc too - Add `tsc` script (tsc --build) at root - Add `build` script to packages/mixpanel; align openfeature provider to `tsc --build` - Update CI to use `npm test` (now covers typecheck) Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

msiebert self-assigned this Mar 19, 2026

msiebert changed the title ~~Add OpenFeature server provider~~ Node: Add OpenFeature server provider Mar 31, 2026

github-advanced-security AI found potential problems Apr 3, 2026

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Comment thread .github/workflows/tests.yml Fixed

msiebert marked this pull request as ready for review April 3, 2026 05:06

msiebert requested review from a team and tylerjroach April 3, 2026 05:06

efahk reviewed Apr 7, 2026

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msiebert requested a review from hans-lizihan April 9, 2026 22:27

msiebert force-pushed the msiebert-openfeature-provider branch from c225f3f to fa9572f Compare April 9, 2026 23:49

msiebert changed the base branch from master to msiebert-sdk-changes April 9, 2026 23:50

msiebert and others added 15 commits April 10, 2026 14:03

Add per-evaluation context support to OpenFeature provider

be450a0

Merge per-evaluation context on top of init context so callers can override or extend context at each flag evaluation, matching the OpenFeature specification. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Add CI job for OpenFeature server provider tests

ef6c1d8

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Pin GitHub Actions to full commit SHAs

1ecae91

Required by repo policy — actions must be pinned to full-length commit SHAs rather than version tags. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Fix CI: add package-lock.json and fix prettier formatting

877abd5

- Track openfeature-server-provider/package-lock.json so npm ci works in CI - Fix prettier formatting in test file Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Bind mixpanel peer dependency to major version

f83336c

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

msiebert changed the base branch from msiebert-sdk-changes to master April 10, 2026 21:04

msiebert force-pushed the msiebert-openfeature-provider branch from fa9572f to 4da0720 Compare April 10, 2026 21:11

msiebert and others added 2 commits April 10, 2026 14:48

Update package-lock.json for 0.21.0 workspace resolution

2caf5cc

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Fix CI: prettier formatting and openfeature working directory path

26199d3

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

msiebert and others added 2 commits April 10, 2026 14:56

Fix CI: exclude packages from root tsc and prettierignore dist

57bb0b9

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

hans-lizihan reviewed Apr 17, 2026

View reviewed changes

msiebert and others added 3 commits April 17, 2026 12:28

Upload coverage to Codecov in CI

cdfb0a7

Both workspace test scripts now emit coverage-final.json; wire it up to codecov-action so PRs get a coverage delta comment. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hans-lizihan approved these changes Apr 17, 2026

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tdumitrescu reviewed Apr 29, 2026

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msiebert and others added 2 commits April 29, 2026 15:58

Reorder test script execution in package.json

8b05ba4

msiebert requested a review from tdumitrescu April 30, 2026 00:09

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Node: Add OpenFeature server provider#255

Node: Add OpenFeature server provider#255
msiebert wants to merge 24 commits intomasterfrom
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msiebert commented Mar 19, 2026

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	"build:workspaces": "npm run build --workspaces --if-present",
	"build": "npm run build --workspaces --if-present",
	"build:workspaces": "npm run build --workspaces --if-present",

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msiebert commented Mar 19, 2026

Summary

Design

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hans-lizihan commented Apr 9, 2026

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