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Merged
pranaygp merged 1 commit into from
Aug 24, 2026
+83 −7
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Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order #3557

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5 changes: 5 additions & 0 deletions .changeset/order-adjacent-hook-deliveries.md
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Open in desktop
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.
80 changes: 76 additions & 4 deletions packages/core/src/delivery-barrier-coverage.test.ts
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
* `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
* result must not overtake the wait/hook branch the log ordered first, however
* many hops that branch needs). Both of those cover a step result deferring
* behind an earlier delivery. This file covers the two cases where the
* behind an earlier delivery. This file covers the three cases where the
* delivery-barrier registry did not yet reach:
*
* 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
* its barrier. They then skipped both the gate and
* `awaitEarlierDeliveries`' macrotask yield.
*
* 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
* must reach their consumers in log order even when the earlier consumer
* takes more microtask hops to act on its value.
*
* (Upstream this file also covers abort deliveries, which participate in the
* registry too. The workflow `AbortController` does not exist on this branch,
* so that case is not portable here.)
*
* Cases 1-2 assert the same thing: the replay allocates its follow-up step
* Cases 1-3 assert the same thing: the replay allocates its follow-up step
* ULIDs in the order the committed log recorded. A regression surfaces as the
* production `ReplayDivergenceError`.
*
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
}
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
const ops: Promise<unknown>[] = [];
const [firstPayload, secondPayload] = await Promise.all([
dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
]);

const events: Event[] = [
event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
token: 'first',
isWebhook: false,
}),
event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
token: 'second',
isWebhook: false,
}),
event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
token: 'first',
payload: firstPayload,
}),
event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
token: 'second',
payload: secondPayload,
}),
event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
stepName: 'afterFirst',
}),
event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
stepName: 'afterSecond',
}),
];

const ctx = setupWorkflowContext(events);
const useStep = createUseStep(ctx);
const createHook = createCreateHook(ctx);

const error = await replay(ctx, async () => {
const first = createHook<{ v: number }>({ token: 'first' });
const second = createHook<{ v: number }>({ token: 'second' });
const afterFirst = useStep('afterFirst');
const afterSecond = useStep('afterSecond');

await Promise.all([
(async () => {
for await (const payload of first) {
void payload;
// Model a layered hook consumer such as an async inbox merger:
// the delivery order must survive its continuation depth.
for (let i = 0; i < 16; i++) {
await Promise.resolve();
}
await afterFirst();
break;
}
})(),
(async () => {
await second;
await afterSecond();
})(),
]);
});

expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
});
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
});
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down
5 changes: 2 additions & 3 deletions packages/core/src/private.ts
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
* Which earlier kinds each delivery kind defers behind. Chosen so that no kind
* blocks on a peer it does not need to:
*
* - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
* are sequential same-entity payloads and must not block one another;
* - a hook defers behind earlier HOOKS, WAITS and STEPS;
* - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
* wait never needs to queue behind another wait;
* - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
* wait-for graph can never contain a cycle.
*/
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
hook: ['wait', 'step'],
hook: ['hook', 'wait', 'step'],
wait: ['hook', 'step'],
step: ['wait', 'hook', 'step'],
};
Expand Down
, 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
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(function() {
function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
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navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
});
};
codeBlock.parentElement.style.position = 'relative';
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addCopyButtons();
// Re-run on dynamic content
var observer = new MutationObserver(addCopyButtons);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order by github-actions[bot] · Pull Request #3557 · vercel/workflow · GitHub
Skip to content
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order#3557

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 Merged

pranaygp
merged 1 commit into

from

Aug 24, 2026

+83

−7

 Merged


Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order
#3557
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5 changes: 5 additions & 0 deletions
.changeset/order-adjacent-hook-deliveries.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.

80 changes: 76 additions & 4 deletions
packages/core/src/delivery-barrier-coverage.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 * `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
 * result must not overtake the wait/hook branch the log ordered first, however
 * many hops that branch needs). Both of those cover a step result deferring
 * behind an earlier delivery. This file covers the two cases where the
 * behind an earlier delivery. This file covers the three cases where the
 * delivery-barrier registry did not yet reach:
 *
 * 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
 * its barrier. They then skipped both the gate and
 * `awaitEarlierDeliveries`' macrotask yield.
 *
 * 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
 * must reach their consumers in log order even when the earlier consumer
 * takes more microtask hops to act on its value.
 *
 * (Upstream this file also covers abort deliveries, which participate in the
 * registry too. The workflow `AbortController` does not exist on this branch,
 * so that case is not portable here.)
 *
 * Cases 1-2 assert the same thing: the replay allocates its follow-up step
 * Cases 1-3 assert the same thing: the replay allocates its follow-up step
 * ULIDs in the order the committed log recorded. A regression surfaces as the
 * production `ReplayDivergenceError`.
 *
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
 }
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
 it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
 const ops: Promise<unknown>[] = [];
 const [firstPayload, secondPayload] = await Promise.all([
 dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
 dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
 ]);

 const events: Event[] = [
 event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
 token: 'first',
 isWebhook: false,
 }),
 event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
 token: 'second',
 isWebhook: false,
 }),
 event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
 token: 'first',
 payload: firstPayload,
 }),
 event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
 token: 'second',
 payload: secondPayload,
 }),
 event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
 stepName: 'afterFirst',
 }),
 event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
 stepName: 'afterSecond',
 }),
 ];

 const ctx = setupWorkflowContext(events);
 const useStep = createUseStep(ctx);
 const createHook = createCreateHook(ctx);

 const error = await replay(ctx, async () => {
 const first = createHook<{ v: number }>({ token: 'first' });
 const second = createHook<{ v: number }>({ token: 'second' });
 const afterFirst = useStep('afterFirst');
 const afterSecond = useStep('afterSecond');

 await Promise.all([
 (async () => {
 for await (const payload of first) {
 void payload;
 // Model a layered hook consumer such as an async inbox merger:
 // the delivery order must survive its continuation depth.
 for (let i = 0; i < 16; i++) {
 await Promise.resolve();
 }
 await afterFirst();
 break;
 }
 })(),
 (async () => {
 await second;
 await afterSecond();
 })(),
 ]);
 });

 expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
 });
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
 });
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down

5 changes: 2 additions & 3 deletions
packages/core/src/private.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
 * Which earlier kinds each delivery kind defers behind. Chosen so that no kind
 * blocks on a peer it does not need to:
 *
 * - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
 * are sequential same-entity payloads and must not block one another;
 * - a hook defers behind earlier HOOKS, WAITS and STEPS;
 * - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
 * wait never needs to queue behind another wait;
 * - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
 * wait-for graph can never contain a cycle.
 */
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
 hook: ['wait', 'step'],
 hook: ['hook', 'wait', 'step'],
 wait: ['hook', 'step'],
 step: ['wait', 'hook', 'step'],
};
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
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} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order by github-actions[bot] · Pull Request #3557 · vercel/workflow · GitHub
Skip to content
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order#3557

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 Merged

pranaygp
merged 1 commit into

from

Aug 24, 2026

+83

−7

 Merged


Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order
#3557
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5 changes: 5 additions & 0 deletions
.changeset/order-adjacent-hook-deliveries.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.

80 changes: 76 additions & 4 deletions
packages/core/src/delivery-barrier-coverage.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 * `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
 * result must not overtake the wait/hook branch the log ordered first, however
 * many hops that branch needs). Both of those cover a step result deferring
 * behind an earlier delivery. This file covers the two cases where the
 * behind an earlier delivery. This file covers the three cases where the
 * delivery-barrier registry did not yet reach:
 *
 * 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
 * its barrier. They then skipped both the gate and
 * `awaitEarlierDeliveries`' macrotask yield.
 *
 * 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
 * must reach their consumers in log order even when the earlier consumer
 * takes more microtask hops to act on its value.
 *
 * (Upstream this file also covers abort deliveries, which participate in the
 * registry too. The workflow `AbortController` does not exist on this branch,
 * so that case is not portable here.)
 *
 * Cases 1-2 assert the same thing: the replay allocates its follow-up step
 * Cases 1-3 assert the same thing: the replay allocates its follow-up step
 * ULIDs in the order the committed log recorded. A regression surfaces as the
 * production `ReplayDivergenceError`.
 *
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
 }
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
 it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
 const ops: Promise<unknown>[] = [];
 const [firstPayload, secondPayload] = await Promise.all([
 dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
 dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
 ]);

 const events: Event[] = [
 event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
 token: 'first',
 isWebhook: false,
 }),
 event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
 token: 'second',
 isWebhook: false,
 }),
 event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
 token: 'first',
 payload: firstPayload,
 }),
 event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
 token: 'second',
 payload: secondPayload,
 }),
 event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
 stepName: 'afterFirst',
 }),
 event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
 stepName: 'afterSecond',
 }),
 ];

 const ctx = setupWorkflowContext(events);
 const useStep = createUseStep(ctx);
 const createHook = createCreateHook(ctx);

 const error = await replay(ctx, async () => {
 const first = createHook<{ v: number }>({ token: 'first' });
 const second = createHook<{ v: number }>({ token: 'second' });
 const afterFirst = useStep('afterFirst');
 const afterSecond = useStep('afterSecond');

 await Promise.all([
 (async () => {
 for await (const payload of first) {
 void payload;
 // Model a layered hook consumer such as an async inbox merger:
 // the delivery order must survive its continuation depth.
 for (let i = 0; i < 16; i++) {
 await Promise.resolve();
 }
 await afterFirst();
 break;
 }
 })(),
 (async () => {
 await second;
 await afterSecond();
 })(),
 ]);
 });

 expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
 });
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
 });
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down

5 changes: 2 additions & 3 deletions
packages/core/src/private.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
 * Which earlier kinds each delivery kind defers behind. Chosen so that no kind
 * blocks on a peer it does not need to:
 *
 * - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
 * are sequential same-entity payloads and must not block one another;
 * - a hook defers behind earlier HOOKS, WAITS and STEPS;
 * - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
 * wait never needs to queue behind another wait;
 * - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
 * wait-for graph can never contain a cycle.
 */
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
 hook: ['wait', 'step'],
 hook: ['hook', 'wait', 'step'],
 wait: ['hook', 'step'],
 step: ['wait', 'hook', 'step'],
};
Expand Down

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// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
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if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
}
}
highlight(document.body);
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var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order by github-actions[bot] · Pull Request #3557 · vercel/workflow · GitHub
Skip to content
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order#3557

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 Merged

pranaygp
merged 1 commit into

from

Aug 24, 2026

+83

−7

 Merged


Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order
#3557
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5 changes: 5 additions & 0 deletions
.changeset/order-adjacent-hook-deliveries.md

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Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.

80 changes: 76 additions & 4 deletions
packages/core/src/delivery-barrier-coverage.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 * `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
 * result must not overtake the wait/hook branch the log ordered first, however
 * many hops that branch needs). Both of those cover a step result deferring
 * behind an earlier delivery. This file covers the two cases where the
 * behind an earlier delivery. This file covers the three cases where the
 * delivery-barrier registry did not yet reach:
 *
 * 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
 * its barrier. They then skipped both the gate and
 * `awaitEarlierDeliveries`' macrotask yield.
 *
 * 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
 * must reach their consumers in log order even when the earlier consumer
 * takes more microtask hops to act on its value.
 *
 * (Upstream this file also covers abort deliveries, which participate in the
 * registry too. The workflow `AbortController` does not exist on this branch,
 * so that case is not portable here.)
 *
 * Cases 1-2 assert the same thing: the replay allocates its follow-up step
 * Cases 1-3 assert the same thing: the replay allocates its follow-up step
 * ULIDs in the order the committed log recorded. A regression surfaces as the
 * production `ReplayDivergenceError`.
 *
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
 }
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
 it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
 const ops: Promise<unknown>[] = [];
 const [firstPayload, secondPayload] = await Promise.all([
 dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
 dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
 ]);

 const events: Event[] = [
 event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
 token: 'first',
 isWebhook: false,
 }),
 event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
 token: 'second',
 isWebhook: false,
 }),
 event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
 token: 'first',
 payload: firstPayload,
 }),
 event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
 token: 'second',
 payload: secondPayload,
 }),
 event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
 stepName: 'afterFirst',
 }),
 event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
 stepName: 'afterSecond',
 }),
 ];

 const ctx = setupWorkflowContext(events);
 const useStep = createUseStep(ctx);
 const createHook = createCreateHook(ctx);

 const error = await replay(ctx, async () => {
 const first = createHook<{ v: number }>({ token: 'first' });
 const second = createHook<{ v: number }>({ token: 'second' });
 const afterFirst = useStep('afterFirst');
 const afterSecond = useStep('afterSecond');

 await Promise.all([
 (async () => {
 for await (const payload of first) {
 void payload;
 // Model a layered hook consumer such as an async inbox merger:
 // the delivery order must survive its continuation depth.
 for (let i = 0; i < 16; i++) {
 await Promise.resolve();
 }
 await afterFirst();
 break;
 }
 })(),
 (async () => {
 await second;
 await afterSecond();
 })(),
 ]);
 });

 expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
 });
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
 });
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down

5 changes: 2 additions & 3 deletions
packages/core/src/private.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
 * Which earlier kinds each delivery kind defers behind. Chosen so that no kind
 * blocks on a peer it does not need to:
 *
 * - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
 * are sequential same-entity payloads and must not block one another;
 * - a hook defers behind earlier HOOKS, WAITS and STEPS;
 * - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
 * wait never needs to queue behind another wait;
 * - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
 * wait-for graph can never contain a cycle.
 */
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
 hook: ['wait', 'step'],
 hook: ['hook', 'wait', 'step'],
 wait: ['hook', 'step'],
 step: ['wait', 'hook', 'step'],
};
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
function cleanUrl(url) {
try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order by github-actions[bot] · Pull Request #3557 · vercel/workflow · GitHub
Skip to content
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order#3557

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 Merged

pranaygp
merged 1 commit into

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Aug 24, 2026

+83

−7

 Merged


Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order
#3557
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5 changes: 5 additions & 0 deletions
.changeset/order-adjacent-hook-deliveries.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.

80 changes: 76 additions & 4 deletions
packages/core/src/delivery-barrier-coverage.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 * `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
 * result must not overtake the wait/hook branch the log ordered first, however
 * many hops that branch needs). Both of those cover a step result deferring
 * behind an earlier delivery. This file covers the two cases where the
 * behind an earlier delivery. This file covers the three cases where the
 * delivery-barrier registry did not yet reach:
 *
 * 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
 * its barrier. They then skipped both the gate and
 * `awaitEarlierDeliveries`' macrotask yield.
 *
 * 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
 * must reach their consumers in log order even when the earlier consumer
 * takes more microtask hops to act on its value.
 *
 * (Upstream this file also covers abort deliveries, which participate in the
 * registry too. The workflow `AbortController` does not exist on this branch,
 * so that case is not portable here.)
 *
 * Cases 1-2 assert the same thing: the replay allocates its follow-up step
 * Cases 1-3 assert the same thing: the replay allocates its follow-up step
 * ULIDs in the order the committed log recorded. A regression surfaces as the
 * production `ReplayDivergenceError`.
 *
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
 }
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
 it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
 const ops: Promise<unknown>[] = [];
 const [firstPayload, secondPayload] = await Promise.all([
 dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
 dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
 ]);

 const events: Event[] = [
 event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
 token: 'first',
 isWebhook: false,
 }),
 event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
 token: 'second',
 isWebhook: false,
 }),
 event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
 token: 'first',
 payload: firstPayload,
 }),
 event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
 token: 'second',
 payload: secondPayload,
 }),
 event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
 stepName: 'afterFirst',
 }),
 event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
 stepName: 'afterSecond',
 }),
 ];

 const ctx = setupWorkflowContext(events);
 const useStep = createUseStep(ctx);
 const createHook = createCreateHook(ctx);

 const error = await replay(ctx, async () => {
 const first = createHook<{ v: number }>({ token: 'first' });
 const second = createHook<{ v: number }>({ token: 'second' });
 const afterFirst = useStep('afterFirst');
 const afterSecond = useStep('afterSecond');

 await Promise.all([
 (async () => {
 for await (const payload of first) {
 void payload;
 // Model a layered hook consumer such as an async inbox merger:
 // the delivery order must survive its continuation depth.
 for (let i = 0; i < 16; i++) {
 await Promise.resolve();
 }
 await afterFirst();
 break;
 }
 })(),
 (async () => {
 await second;
 await afterSecond();
 })(),
 ]);
 });

 expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
 });
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
 });
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down

5 changes: 2 additions & 3 deletions
packages/core/src/private.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
 * Which earlier kinds each delivery kind defers behind. Chosen so that no kind
 * blocks on a peer it does not need to:
 *
 * - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
 * are sequential same-entity payloads and must not block one another;
 * - a hook defers behind earlier HOOKS, WAITS and STEPS;
 * - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
 * wait never needs to queue behind another wait;
 * - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
 * wait-for graph can never contain a cycle.
 */
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
 hook: ['wait', 'step'],
 hook: ['hook', 'wait', 'step'],
 wait: ['hook', 'step'],
 step: ['wait', 'hook', 'step'],
};
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order by github-actions[bot] · Pull Request #3557 · vercel/workflow · GitHub
Skip to content
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order#3557

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 Merged

pranaygp
merged 1 commit into

from

Aug 24, 2026

+83

−7

 Merged


Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order
#3557
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5 changes: 5 additions & 0 deletions
.changeset/order-adjacent-hook-deliveries.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.

80 changes: 76 additions & 4 deletions
packages/core/src/delivery-barrier-coverage.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 * `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
 * result must not overtake the wait/hook branch the log ordered first, however
 * many hops that branch needs). Both of those cover a step result deferring
 * behind an earlier delivery. This file covers the two cases where the
 * behind an earlier delivery. This file covers the three cases where the
 * delivery-barrier registry did not yet reach:
 *
 * 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
 * its barrier. They then skipped both the gate and
 * `awaitEarlierDeliveries`' macrotask yield.
 *
 * 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
 * must reach their consumers in log order even when the earlier consumer
 * takes more microtask hops to act on its value.
 *
 * (Upstream this file also covers abort deliveries, which participate in the
 * registry too. The workflow `AbortController` does not exist on this branch,
 * so that case is not portable here.)
 *
 * Cases 1-2 assert the same thing: the replay allocates its follow-up step
 * Cases 1-3 assert the same thing: the replay allocates its follow-up step
 * ULIDs in the order the committed log recorded. A regression surfaces as the
 * production `ReplayDivergenceError`.
 *
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
 }
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
 it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
 const ops: Promise<unknown>[] = [];
 const [firstPayload, secondPayload] = await Promise.all([
 dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
 dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
 ]);

 const events: Event[] = [
 event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
 token: 'first',
 isWebhook: false,
 }),
 event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
 token: 'second',
 isWebhook: false,
 }),
 event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
 token: 'first',
 payload: firstPayload,
 }),
 event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
 token: 'second',
 payload: secondPayload,
 }),
 event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
 stepName: 'afterFirst',
 }),
 event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
 stepName: 'afterSecond',
 }),
 ];

 const ctx = setupWorkflowContext(events);
 const useStep = createUseStep(ctx);
 const createHook = createCreateHook(ctx);

 const error = await replay(ctx, async () => {
 const first = createHook<{ v: number }>({ token: 'first' });
 const second = createHook<{ v: number }>({ token: 'second' });
 const afterFirst = useStep('afterFirst');
 const afterSecond = useStep('afterSecond');

 await Promise.all([
 (async () => {
 for await (const payload of first) {
 void payload;
 // Model a layered hook consumer such as an async inbox merger:
 // the delivery order must survive its continuation depth.
 for (let i = 0; i < 16; i++) {
 await Promise.resolve();
 }
 await afterFirst();
 break;
 }
 })(),
 (async () => {
 await second;
 await afterSecond();
 })(),
 ]);
 });

 expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
 });
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
 });
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down

5 changes: 2 additions & 3 deletions
packages/core/src/private.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
 * Which earlier kinds each delivery kind defers behind. Chosen so that no kind
 * blocks on a peer it does not need to:
 *
 * - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
 * are sequential same-entity payloads and must not block one another;
 * - a hook defers behind earlier HOOKS, WAITS and STEPS;
 * - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
 * wait never needs to queue behind another wait;
 * - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
 * wait-for graph can never contain a cycle.
 */
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
 hook: ['wait', 'step'],
 hook: ['hook', 'wait', 'step'],
 wait: ['hook', 'step'],
 step: ['wait', 'hook', 'step'],
};
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order by github-actions[bot] · Pull Request #3557 · vercel/workflow · GitHub
Skip to content
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order#3557

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 Merged

pranaygp
merged 1 commit into

from

Aug 24, 2026

+83

−7

 Merged


Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order
#3557
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5 changes: 5 additions & 0 deletions
.changeset/order-adjacent-hook-deliveries.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.

80 changes: 76 additions & 4 deletions
packages/core/src/delivery-barrier-coverage.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 * `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
 * result must not overtake the wait/hook branch the log ordered first, however
 * many hops that branch needs). Both of those cover a step result deferring
 * behind an earlier delivery. This file covers the two cases where the
 * behind an earlier delivery. This file covers the three cases where the
 * delivery-barrier registry did not yet reach:
 *
 * 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
 * its barrier. They then skipped both the gate and
 * `awaitEarlierDeliveries`' macrotask yield.
 *
 * 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
 * must reach their consumers in log order even when the earlier consumer
 * takes more microtask hops to act on its value.
 *
 * (Upstream this file also covers abort deliveries, which participate in the
 * registry too. The workflow `AbortController` does not exist on this branch,
 * so that case is not portable here.)
 *
 * Cases 1-2 assert the same thing: the replay allocates its follow-up step
 * Cases 1-3 assert the same thing: the replay allocates its follow-up step
 * ULIDs in the order the committed log recorded. A regression surfaces as the
 * production `ReplayDivergenceError`.
 *
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
 }
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
 it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
 const ops: Promise<unknown>[] = [];
 const [firstPayload, secondPayload] = await Promise.all([
 dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
 dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
 ]);

 const events: Event[] = [
 event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
 token: 'first',
 isWebhook: false,
 }),
 event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
 token: 'second',
 isWebhook: false,
 }),
 event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
 token: 'first',
 payload: firstPayload,
 }),
 event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
 token: 'second',
 payload: secondPayload,
 }),
 event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
 stepName: 'afterFirst',
 }),
 event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
 stepName: 'afterSecond',
 }),
 ];

 const ctx = setupWorkflowContext(events);
 const useStep = createUseStep(ctx);
 const createHook = createCreateHook(ctx);

 const error = await replay(ctx, async () => {
 const first = createHook<{ v: number }>({ token: 'first' });
 const second = createHook<{ v: number }>({ token: 'second' });
 const afterFirst = useStep('afterFirst');
 const afterSecond = useStep('afterSecond');

 await Promise.all([
 (async () => {
 for await (const payload of first) {
 void payload;
 // Model a layered hook consumer such as an async inbox merger:
 // the delivery order must survive its continuation depth.
 for (let i = 0; i < 16; i++) {
 await Promise.resolve();
 }
 await afterFirst();
 break;
 }
 })(),
 (async () => {
 await second;
 await afterSecond();
 })(),
 ]);
 });

 expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
 });
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
 });
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down

5 changes: 2 additions & 3 deletions
packages/core/src/private.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
 * Which earlier kinds each delivery kind defers behind. Chosen so that no kind
 * blocks on a peer it does not need to:
 *
 * - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
 * are sequential same-entity payloads and must not block one another;
 * - a hook defers behind earlier HOOKS, WAITS and STEPS;
 * - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
 * wait never needs to queue behind another wait;
 * - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
 * wait-for graph can never contain a cycle.
 */
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
 hook: ['wait', 'step'],
 hook: ['hook', 'wait', 'step'],
 wait: ['hook', 'step'],
 step: ['wait', 'hook', 'step'],
};
Expand Down

, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();
Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order by github-actions[bot] · Pull Request #3557 · vercel/workflow · GitHub
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 Merged

pranaygp
merged 1 commit into

from

Aug 24, 2026

+83

−7

 Merged


Backport #3552: fix(core): replay ordering - preserve adjacent hook delivery order
#3557
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5 changes: 5 additions & 0 deletions
.changeset/order-adjacent-hook-deliveries.md

View file


Open in desktop

Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
---
'@workflow/core': patch
---

Preserve event-log order when adjacent hook payloads resume independent workflow branches.

80 changes: 76 additions & 4 deletions
packages/core/src/delivery-barrier-coverage.test.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -3,7 +3,7 @@
 * `CORRUPTED_EVENT_LOG` shapes) and `step-delivery-hop-count.test.ts` (a step
 * result must not overtake the wait/hook branch the log ordered first, however
 * many hops that branch needs). Both of those cover a step result deferring
 * behind an earlier delivery. This file covers the two cases where the
 * behind an earlier delivery. This file covers the three cases where the
 * delivery-barrier registry did not yet reach:
 *
 * 1. STEP behind STEP, across drain windows. `DEFER_BEHIND.step` used to
Expand All@@ -20,11 +20,15 @@
 * its barrier. They then skipped both the gate and
 * `awaitEarlierDeliveries`' macrotask yield.
 *
 * 3. HOOK behind HOOK. Adjacent payloads for independently awaited hooks
 * must reach their consumers in log order even when the earlier consumer
 * takes more microtask hops to act on its value.
 *
 * (Upstream this file also covers abort deliveries, which participate in the
 * registry too. The workflow `AbortController` does not exist on this branch,
 * so that case is not portable here.)
 *
 * Cases 1-2 assert the same thing: the replay allocates its follow-up step
 * Cases 1-3 assert the same thing: the replay allocates its follow-up step
 * ULIDs in the order the committed log recorded. A regression surfaces as the
 * production `ReplayDivergenceError`.
 *
Expand DownExpand Up@@ -394,7 +398,75 @@ describe('hook payload delivery ordering against an earlier step result', () =>
 }
});

// ─── 3. registry scan cost ─────────────────────────────────────────────────
// ─── 3. hook behind hook, across different consumer shapes ─────────────────
describe('hook payload delivery ordering against an earlier hook payload', () => {
 it('keeps the recorded ULID allocation when the earlier hook uses an async iterator', async () => {
 const ops: Promise<unknown>[] = [];
 const [firstPayload, secondPayload] = await Promise.all([
 dehydrateStepReturnValue({ v: 1 }, 'wrun_test', undefined, ops),
 dehydrateStepReturnValue({ v: 2 }, 'wrun_test', undefined, ops),
 ]);

 const events: Event[] = [
 event('evnt_0', 'hook_created', `hook_${ULIDS[0]}`, {
 token: 'first',
 isWebhook: false,
 }),
 event('evnt_1', 'hook_created', `hook_${ULIDS[1]}`, {
 token: 'second',
 isWebhook: false,
 }),
 event('evnt_2', 'hook_received', `hook_${ULIDS[0]}`, {
 token: 'first',
 payload: firstPayload,
 }),
 event('evnt_3', 'hook_received', `hook_${ULIDS[1]}`, {
 token: 'second',
 payload: secondPayload,
 }),
 event('evnt_4', 'step_created', `step_${ULIDS[2]}`, {
 stepName: 'afterFirst',
 }),
 event('evnt_5', 'step_created', `step_${ULIDS[3]}`, {
 stepName: 'afterSecond',
 }),
 ];

 const ctx = setupWorkflowContext(events);
 const useStep = createUseStep(ctx);
 const createHook = createCreateHook(ctx);

 const error = await replay(ctx, async () => {
 const first = createHook<{ v: number }>({ token: 'first' });
 const second = createHook<{ v: number }>({ token: 'second' });
 const afterFirst = useStep('afterFirst');
 const afterSecond = useStep('afterSecond');

 await Promise.all([
 (async () => {
 for await (const payload of first) {
 void payload;
 // Model a layered hook consumer such as an async inbox merger:
 // the delivery order must survive its continuation depth.
 for (let i = 0; i < 16; i++) {
 await Promise.resolve();
 }
 await afterFirst();
 break;
 }
 })(),
 (async () => {
 await second;
 await afterSecond();
 })(),
 ]);
 });

 expectSuspendedWithPendingSteps(ctx, error, ['afterFirst', 'afterSecond']);
 });
});

// ─── 4. registry scan cost ─────────────────────────────────────────────────
//
// `resolvesOnItsOwn` walks the registry recursively: an armed hook re-checks
// every earlier wait and step, an armed wait every earlier hook and step, and
Expand DownExpand Up@@ -432,7 +504,7 @@ describe('delivery-barrier registry scan cost', () => {
 });
});

// ─── 4. suspension timing: idle must wait out parked deliveries ────────────
// ─── 5. suspension timing: idle must wait out parked deliveries ────────────
//
// Field shape from vercel/workflow#3183: a fire-and-forget `sleep()` (a
// watchdog — never awaited, never completing in-run) plus a parallel batch of
Expand Down

5 changes: 2 additions & 3 deletions
packages/core/src/private.ts

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -235,8 +235,7 @@ interface DeliveryBarrierEntry {
 * Which earlier kinds each delivery kind defers behind. Chosen so that no kind
 * blocks on a peer it does not need to:
 *
 * - a hook defers behind earlier WAITS and STEPS — not earlier hooks, which
 * are sequential same-entity payloads and must not block one another;
 * - a hook defers behind earlier HOOKS, WAITS and STEPS;
 * - a wait defers behind earlier HOOKS and STEPS — not earlier waits, since a
 * wait never needs to queue behind another wait;
 * - a step defers behind earlier WAITS, HOOKS and STEPS.
Expand All@@ -259,7 +258,7 @@ interface DeliveryBarrierEntry {
 * wait-for graph can never contain a cycle.
 */
const DEFER_BEHIND: Record<DeliveryKind, readonly DeliveryKind[]> = {
 hook: ['wait', 'step'],
 hook: ['hook', 'wait', 'step'],
 wait: ['hook', 'step'],
 step: ['wait', 'hook', 'step'],
};
Expand Down