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[APPS-2792] Add: local-execution resilience tests (Milestone 7) - #492
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…des (Milestone 7) Two targeted resilience checks, not fixes — Milestone 7 in the Kickoff doc exists to empirically confirm the actual failure modes of running backend functions in-process (no child process/thread isolation) before deciding whether closing them is worth the cost the RFC already weighed against fork()-based isolation. Confirmed: a synchronous CPU-bound loop starves the event loop entirely, so the current Promise.race timeout never gets a chance to fire — it can only settle once the loop finishes on its own. Confirmed via a real child process: process.exit() inside the customer function terminates the whole process immediately, bypassing try/finally cleanup entirely — no JS-level exception handling in this design can intercept it, so this takes the whole dev server down, not just its own execution.
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Motivation
domains/chaos-engineeringtargets Datadog-owned Kubernetes clusters, a mismatch for this in-process, customer-dev-server model.Changes
Promise.racetimeout never gets a chance to fire — it can only settle once the loop finishes on its own.process.exit()can't safely run inside this same Jest process) confirmingprocess.exit()inside the customer function terminates the whole process immediately, bypassingtry/finallycleanup entirely.The third Milestone 7 task ("the queue survives a rejected execution and keeps running") was already covered by an existing test in
local-execution.test.ts, per the Kickoff doc's own checklist.QA Instructions
yarn workspace @dd/tests test:unit packages/plugins/apps/src/vite/local-execution.resilience.test.ts # Expected: 2 passed ✅ VERIFIEDyarn workspace @dd/tests test:unit packages/plugins/apps # Expected: 25 suites / 324 tests passed ✅ VERIFIEDyarn workspace @dd/apps-plugin run typecheck # Expected: clean exit ✅ VERIFIEDBlast Radius
Out of Scope / Follow-ups
worker_threads) to close the confirmed sync-hang andprocess.exit()gapsDocumentation