fix(process): attribute slow memory Worker requests

[justinhelmer]

Memory Worker tests now allow cold Durable Object startup and record which request is slow or still pending when a case fails. Related to #2119; this does not close it.

Why: After #2440, a multi-request transcript case exceeded the 5-second case limit on #2444 (5.53 seconds), then passed on the same head. A 50-run Linux probe measured one first /runs/transcript/owner request at 1.82 seconds while the following seven requests were fast. The old limit hid which request consumed the time. That probe supports a cold-start explanation but does not prove the failed request had the same cause.

Where to look

1. Case deadline gives multi-request cases 15 seconds.
2. Operation capture records route, outcome and duration in each test artifact.
3. Shared test fetch records every routed request, including direct calls outside the post helpers.
4. Failure summary prints pending routes and recent requests without flooding CI logs.
5. Behavior proof keeps the remaining reliability gap explicit.

Feedback wanted: Check the 15-second case bound and whether the request markers identify the stalled operation if the flake returns.

Risk: A genuinely stalled case can take 10 seconds longer to fail. This changes the test harness only; the production Worker is unchanged. #2119 stays open for live CI evidence.

Verified: 50/50 fresh Linux suite runs on five Depot runners at the final head, 50/50 on each of two prior candidates, and 70/70 baseline runs. All exact-head PR checks passed. Local named Worker tests: 225 passed, one expected failure; four diagnostic tests passed. Worker and root typechecks, consistency, spec coverage and formatting passed. Current PR-head CI is pending.

Decisions (1)

• Measure requests, not just cases. The case can make several real Durable Object requests. The artifact retains every request; CI prints a bounded summary. A passing retry alone does not identify a root cause, so ci: the memory Worker verify is flaky on Depot — workerd cancels a hung request, a different test fails each run #2119 remains open.

Validation (3 criteria)

Criterion	Proof
A timed-out case records completed and pending request labels, including a stalled response body.	src/memoryWorkerDiagnostics.test.ts: the stalled-route and stalled-body fixtures pass.
The Worker suite retains its assertions and passes repeatedly on Linux.	Depot exact-head probe: five jobs, 10 fresh suite processes each, 0 failures on 4bcc8765a.
Generated and declared artifacts match the source.	npm run check:consistency and specs:coverage --require passed locally.

[coreplane-switchboard]

Changes requested: The new request diagnostics can mark a stalled response as complete.

Warning

Changes requested · head af51486 · 1 finding: 1 minor

Severity	Finding	Where
minor	F1 Keep request diagnostics open through response-body consumption	deploy/cloudflare-memory/testFetch.ts:8

Full review

F1 (minor, high confidence): fetchMemoryTest marks a request passed as soon as SELF.fetch returns, but the test helpers read res.text() or res.json() afterward. If a response body stalls, the case can time out while the diagnostic reports that route as completed and shows no pending request. Keep the operation open through body consumption, and cover that timeout in the fixture test.

[coreplane-switchboard]

LGTM: The prior response-body attribution gap is closed; no remaining findings in the complete PR diff.

Note

Approved · head 4bcc876 · no findings

Full review

The prior F1 is resolved: the operation stays pending through response-body consumption, and a stalled-body regression test covers it. No further findings.

[coreplane-switchboard]

LGTM: The request instrumentation and longer Worker test deadline preserve the existing assertions and add useful timeout diagnostics.

Note

Approved · head 4bcc876 · no findings

Full review

No findings.

[github-actions]

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[github-actions]

Auto-approved: coreplane-switchboard[bot] reviewed this PR and posted an LGTM verdict (see its review). This repository opted in through its REVIEW_BOT_LOGIN and REVIEW_BOT_ID variables.