Summary

This PR adds Bun runtime support to @pyroscope/nodejs by updating the @datadog/pprof dependency to a Bun-compatible version.

Fixes #228

Problem

Bun is not currently supported because the upstream @datadog/pprof dependency crashes when loaded in Bun:

bun -e "import Pyroscope from '@pyroscope/nodejs'"
# => segfault in @datadog/pprof native addon

Solution

Updates the @datadog/pprof dependency to a fork that includes a pure JavaScript backend for Bun, avoiding the native addon crashes.

Upstream PR

This PR depends on: DataDog/pprof-nodejs#263

Once the upstream PR is merged and released, this dependency should be updated to the official npm package.

Changes

• Updated package.json: Changed @datadog/pprof to use the Bun-compatible fork
• Added tools/bun-smoke.mjs - End-to-end integration test for Bun
• Added CI: Bun smoke tests on linux-x64, linux-arm64, darwin-arm64
• CI gates releases on Bun smoke tests passing

Verification

Tested on:

• ✅ Bun v1.3.5+
• ✅ linux-x64, linux-arm64, darwin-arm64

Full Integration Test

The smoke test (tools/bun-smoke.mjs) validates:

1. Import and lifecycle (init(), start(), stop())
2. Express middleware endpoints (/debug/pprof/profile, /debug/pprof/heap)
3. Continuous profiling export to Pyroscope
4. Tags and labels

# Run the smoke test
yarn bun:smoke
# => {"ok":true,"heapBytes":...,"wallBytes":...,"ingestRequests":1}

Manual Test

# Lifecycle
bun -e "import pyroscope from '@pyroscope/nodejs'; pyroscope.init({appName:'test'}); pyroscope.start(); await pyroscope.stop(); console.log('ok')"
# => ok

# With express middleware
bun -e "
import express from 'express';
import Pyroscope from '@pyroscope/nodejs';
const app = express();
app.use(Pyroscope.expressMiddleware());
Pyroscope.init({appName:'test'});
Pyroscope.start();
console.log('Server with profiling ready');
"

Testing

• Bun smoke tests pass on linux-x64
• Bun smoke tests pass on linux-arm64
• Bun smoke tests pass on darwin-arm64
• Existing Node.js tests still pass
• Update dependency once upstream PR is merged

Checklist

• I have added tests that prove my fix is effective or that my feature works
• I have added CI coverage for the new feature
• Tests pass locally and in CI
• Documentation updated (will do after upstream merge)
• Dependency updated to official package (after upstream merge)

Breaking Changes

None. This change only adds Bun support without affecting existing Node.js functionality.