stream: preserve falsy cancellation reasons#64705

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nodejs-github-bot merged 1 commit into from
Aug 14, 2026
Merged

stream: preserve falsy cancellation reasons #64705

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10 changes: 6 additions & 4 deletions lib/internal/streams/iter/broadcast.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
#consumers = new SafeSet();
#waiters = []; // Consumers with pending resolve (subset of #consumers)
#ended = false;
#error = null;
#error;
#cancelled = false;
#options;
#writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
__proto__: null,
next() {
if (state.detached) {
if (self.#error) return PromiseReject(self.#error);
if (self.#error !== undefined) {
return PromiseReject(self.#error);
}
return kDone;
}

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
{ __proto__: null, done: false, value: chunk });
}

if (self.#error) {
if (self.#error !== undefined) {
state.detached = true;
self.#deleteConsumer(state);
return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
}

[kAbort](reason) {
if (this.#ended || this.#error) return;
if (this.#ended || this.#error !== undefined) return;
this.#error = reason;
this.#ended = true;

Expand Down
26 changes: 14 additions & 12 deletions lib/internal/streams/iter/share.js
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Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
#consumers = new SafeSet();
#sourceIterator = null;
#sourceExhausted = false;
#sourceError = null;
#sourceError;
#cancelled = false;
#pulling = false;
#pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
__proto__: null,
[SymbolAsyncIterator]() {
const getNext = async () => {
if (self.#sourceError) {
if (self.#sourceError !== undefined) {
state.detached = true;
self.#consumers.delete(state);
throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
// cursor must re-pull rather than terminating prematurely.
for (;;) {
if (state.detached) {
if (self.#sourceError) throw self.#sourceError;
if (self.#sourceError !== undefined) throw self.#sourceError;
return { __proto__: null, done: true, value: undefined };
}

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
if (self.#sourceExhausted) {
state.detached = true;
self.#deleteConsumer(state);
if (self.#sourceError) throw self.#sourceError;
if (self.#sourceError !== undefined) throw self.#sourceError;
return { __proto__: null, done: true, value: undefined };
}

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
if (shouldBuffer === null) {
state.detached = true;
self.#deleteConsumer(state);
if (self.#sourceError) throw self.#sourceError;
if (self.#sourceError !== undefined) throw self.#sourceError;
return { __proto__: null, done: true, value: undefined };
}

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

async #waitForBufferSpace() {
while (this.#bufferedBytes >= this.#options.budget) {
if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
if (this.#cancelled ||
this.#sourceError !== undefined ||
this.#sourceExhausted) {
return this.#cancelled ? null : true;
}

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
#consumers = new SafeSet();
#sourceIterator = null;
#sourceExhausted = false;
#sourceError = null;
#sourceError;
#cancelled = false;
#cachedMinCursor = 0;
#cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
return {
__proto__: null,
next() {
if (state.detached) {
return { __proto__: null, done: true, value: undefined };
}
if (self.#sourceError) {
if (self.#sourceError !== undefined) {
state.detached = true;
self.#deleteConsumer(state);
throw self.#sourceError;
}
if (state.detached) {
return { __proto__: null, done: true, value: undefined };
}
if (self.#cancelled) {
state.detached = true;
self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

self.#pullFromSource();

if (self.#sourceError) {
if (self.#sourceError !== undefined) {
state.detached = true;
self.#deleteConsumer(state);
throw self.#sourceError;
Expand Down
16 changes: 8 additions & 8 deletions test/parallel/test-stream-iter-broadcast-basic.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
}, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
const { broadcast: bc } = broadcast();
const consumer = bc.push();
const resultPromise = text(consumer).catch((err) => err);
await new Promise((resolve) => setImmediate(resolve));
bc.cancel(0);
const result = await resultPromise;
assert.strictEqual(result, 0);
for (const reason of [0, '', false, null]) {
const { broadcast: bc } = broadcast();
const iterator = bc.push()[Symbol.asyncIterator]();

bc.cancel(reason);

await assert.rejects(iterator.next(), (error) => error === reason);
}
}

// Late-joining consumer should read from oldest buffered entry
Expand Down
12 changes: 12 additions & 0 deletions test/parallel/test-stream-iter-share-async.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
);
}

async function testShareCancelWithFalsyReason() {
for (const reason of [0, '', false, null]) {
const shared = share(from('data'));
const iterator = shared.pull()[Symbol.asyncIterator]();

shared.cancel(reason);

await assert.rejects(iterator.next(), (error) => error === reason);
}
}

async function testShareAbortSignal() {
const ac = new AbortController();
const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
testShareCancel(),
testShareCancelMidIteration(),
testShareCancelWithReason(),
testShareCancelWithFalsyReason(),
testShareAbortSignal(),
testShareAbortSignalWhileSourcePullPending(),
testSharePullAbortSignalRejectsPendingNext(),
Expand Down
36 changes: 16 additions & 20 deletions test/parallel/test-stream-iter-share-sync.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
// When cancel(reason) is called, a consumer that hasn't started
// iterating is already detached, so it sees done:true (not the error).
// But a consumer that is mid-iteration when another consumer cancels
// with a reason will see the error on the next pull after cancel.
const enc = new TextEncoder();
function* gen() {
yield [enc.encode('a')];
yield [enc.encode('b')];
yield [enc.encode('c')];
}
const shared = shareSync(gen(), { budget: 16384 });
const c1 = shared.pull();
const c2 = shared.pull();
const iterator1 = shared.pull()[Symbol.iterator]();
const iterator2 = shared.pull()[Symbol.iterator]();
const reason = new Error('sync cancel reason');

iterator1.next();
shared.cancel(reason);

// c1 reads one item, then c2 cancels with a reason
const iter1 = c1[Symbol.iterator]();
const first = iter1.next();
assert.strictEqual(first.done, false);
assert.throws(() => iterator1.next(), (error) => error === reason);
assert.throws(() => iterator2.next(), (error) => error === reason);
}

shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
for (const reason of [0, '', false, null]) {
const shared = shareSync(fromSync('data'));
const iterator = shared.pull()[Symbol.iterator]();

// c1 was already iterating, it's now detached → done
const next = iter1.next();
assert.strictEqual(next.done, true);
shared.cancel(reason);

// c2 never started, also detached → done (not error)
const batches = [];
for (const batch of c2) {
batches.push(batch);
assert.throws(() => iterator.next(), (error) => error === reason);
}
assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
testShareSyncCancel(),
testShareSyncCancelMidIteration(),
testShareSyncCancelWithReason(),
testShareSyncCancelWithFalsyReason(),
testShareSyncSourceError(),
testShareSyncStringSource(),
]).then(common.mustCall());
Loading
, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
stream: preserve falsy cancellation reasons#64705

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to your account

 Merged

nodejs-github-bot
merged 1 commit into

from

Aug 14, 2026
 Merged


stream: preserve falsy cancellation reasons
#64705
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10 changes: 6 additions & 4 deletions
lib/internal/streams/iter/broadcast.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
 #consumers = new SafeSet();
 #waiters = []; // Consumers with pending resolve (subset of #consumers)
 #ended = false;
 #error = null;
 #error;
 #cancelled = false;
 #options;
 #writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
 __proto__: null,
 next() {
 if (state.detached) {
 if (self.#error) return PromiseReject(self.#error);
 if (self.#error !== undefined) {
 return PromiseReject(self.#error);
 }
 return kDone;
 }

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
 { __proto__: null, done: false, value: chunk });
 }

 if (self.#error) {
 if (self.#error !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
 }

 [kAbort](reason) {
 if (this.#ended || this.#error) return;
 if (this.#ended || this.#error !== undefined) return;
 this.#error = reason;
 this.#ended = true;

Expand Down

26 changes: 14 additions & 12 deletions
lib/internal/streams/iter/share.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #pulling = false;
 #pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
 __proto__: null,
 [SymbolAsyncIterator]() {
 const getNext = async () => {
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#consumers.delete(state);
 throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
 // cursor must re-pull rather than terminating prematurely.
 for (;;) {
 if (state.detached) {
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
 if (self.#sourceExhausted) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
 if (shouldBuffer === null) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

 async #waitForBufferSpace() {
 while (this.#bufferedBytes >= this.#options.budget) {
 if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
 if (this.#cancelled ||
 this.#sourceError !== undefined ||
 this.#sourceExhausted) {
 return this.#cancelled ? null : true;
 }

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #cachedMinCursor = 0;
 #cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
 return {
 __proto__: null,
 next() {
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
 }
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#cancelled) {
 state.detached = true;
 self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

 self.#pullFromSource();

 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
Expand Down

16 changes: 8 additions & 8 deletions
test/parallel/test-stream-iter-broadcast-basic.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
 }, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
 const { broadcast: bc } = broadcast();
 const consumer = bc.push();
 const resultPromise = text(consumer).catch((err) => err);
 await new Promise((resolve) => setImmediate(resolve));
 bc.cancel(0);
 const result = await resultPromise;
 assert.strictEqual(result, 0);
 for (const reason of [0, '', false, null]) {
 const { broadcast: bc } = broadcast();
 const iterator = bc.push()[Symbol.asyncIterator]();

 bc.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

// Late-joining consumer should read from oldest buffered entry
Expand Down

12 changes: 12 additions & 0 deletions
test/parallel/test-stream-iter-share-async.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
 );
}

async function testShareCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = share(from('data'));
 const iterator = shared.pull()[Symbol.asyncIterator]();

 shared.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

async function testShareAbortSignal() {
 const ac = new AbortController();
 const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
 testShareCancel(),
 testShareCancelMidIteration(),
 testShareCancelWithReason(),
 testShareCancelWithFalsyReason(),
 testShareAbortSignal(),
 testShareAbortSignalWhileSourcePullPending(),
 testSharePullAbortSignalRejectsPendingNext(),
Expand Down

36 changes: 16 additions & 20 deletions
test/parallel/test-stream-iter-share-sync.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
 // When cancel(reason) is called, a consumer that hasn't started
 // iterating is already detached, so it sees done:true (not the error).
 // But a consumer that is mid-iteration when another consumer cancels
 // with a reason will see the error on the next pull after cancel.
 const enc = new TextEncoder();
 function* gen() {
 yield [enc.encode('a')];
 yield [enc.encode('b')];
 yield [enc.encode('c')];
 }
 const shared = shareSync(gen(), { budget: 16384 });
 const c1 = shared.pull();
 const c2 = shared.pull();
 const iterator1 = shared.pull()[Symbol.iterator]();
 const iterator2 = shared.pull()[Symbol.iterator]();
 const reason = new Error('sync cancel reason');

 iterator1.next();
 shared.cancel(reason);

 // c1 reads one item, then c2 cancels with a reason
 const iter1 = c1[Symbol.iterator]();
 const first = iter1.next();
 assert.strictEqual(first.done, false);
 assert.throws(() => iterator1.next(), (error) => error === reason);
 assert.throws(() => iterator2.next(), (error) => error === reason);
}

 shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = shareSync(fromSync('data'));
 const iterator = shared.pull()[Symbol.iterator]();

 // c1 was already iterating, it's now detached → done
 const next = iter1.next();
 assert.strictEqual(next.done, true);
 shared.cancel(reason);

 // c2 never started, also detached → done (not error)
 const batches = [];
 for (const batch of c2) {
 batches.push(batch);
 assert.throws(() => iterator.next(), (error) => error === reason);
 }
 assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
 testShareSyncCancel(),
 testShareSyncCancelMidIteration(),
 testShareSyncCancelWithReason(),
 testShareSyncCancelWithFalsyReason(),
 testShareSyncSourceError(),
 testShareSyncStringSource(),
]).then(common.mustCall());
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
stream: preserve falsy cancellation reasons#64705

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
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to your account

 Merged

nodejs-github-bot
merged 1 commit into

from

Aug 14, 2026
 Merged


stream: preserve falsy cancellation reasons
#64705
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10 changes: 6 additions & 4 deletions
lib/internal/streams/iter/broadcast.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
 #consumers = new SafeSet();
 #waiters = []; // Consumers with pending resolve (subset of #consumers)
 #ended = false;
 #error = null;
 #error;
 #cancelled = false;
 #options;
 #writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
 __proto__: null,
 next() {
 if (state.detached) {
 if (self.#error) return PromiseReject(self.#error);
 if (self.#error !== undefined) {
 return PromiseReject(self.#error);
 }
 return kDone;
 }

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
 { __proto__: null, done: false, value: chunk });
 }

 if (self.#error) {
 if (self.#error !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
 }

 [kAbort](reason) {
 if (this.#ended || this.#error) return;
 if (this.#ended || this.#error !== undefined) return;
 this.#error = reason;
 this.#ended = true;

Expand Down

26 changes: 14 additions & 12 deletions
lib/internal/streams/iter/share.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #pulling = false;
 #pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
 __proto__: null,
 [SymbolAsyncIterator]() {
 const getNext = async () => {
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#consumers.delete(state);
 throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
 // cursor must re-pull rather than terminating prematurely.
 for (;;) {
 if (state.detached) {
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
 if (self.#sourceExhausted) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
 if (shouldBuffer === null) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

 async #waitForBufferSpace() {
 while (this.#bufferedBytes >= this.#options.budget) {
 if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
 if (this.#cancelled ||
 this.#sourceError !== undefined ||
 this.#sourceExhausted) {
 return this.#cancelled ? null : true;
 }

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #cachedMinCursor = 0;
 #cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
 return {
 __proto__: null,
 next() {
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
 }
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#cancelled) {
 state.detached = true;
 self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

 self.#pullFromSource();

 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
Expand Down

16 changes: 8 additions & 8 deletions
test/parallel/test-stream-iter-broadcast-basic.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
 }, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
 const { broadcast: bc } = broadcast();
 const consumer = bc.push();
 const resultPromise = text(consumer).catch((err) => err);
 await new Promise((resolve) => setImmediate(resolve));
 bc.cancel(0);
 const result = await resultPromise;
 assert.strictEqual(result, 0);
 for (const reason of [0, '', false, null]) {
 const { broadcast: bc } = broadcast();
 const iterator = bc.push()[Symbol.asyncIterator]();

 bc.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

// Late-joining consumer should read from oldest buffered entry
Expand Down

12 changes: 12 additions & 0 deletions
test/parallel/test-stream-iter-share-async.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
 );
}

async function testShareCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = share(from('data'));
 const iterator = shared.pull()[Symbol.asyncIterator]();

 shared.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

async function testShareAbortSignal() {
 const ac = new AbortController();
 const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
 testShareCancel(),
 testShareCancelMidIteration(),
 testShareCancelWithReason(),
 testShareCancelWithFalsyReason(),
 testShareAbortSignal(),
 testShareAbortSignalWhileSourcePullPending(),
 testSharePullAbortSignalRejectsPendingNext(),
Expand Down

36 changes: 16 additions & 20 deletions
test/parallel/test-stream-iter-share-sync.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
 // When cancel(reason) is called, a consumer that hasn't started
 // iterating is already detached, so it sees done:true (not the error).
 // But a consumer that is mid-iteration when another consumer cancels
 // with a reason will see the error on the next pull after cancel.
 const enc = new TextEncoder();
 function* gen() {
 yield [enc.encode('a')];
 yield [enc.encode('b')];
 yield [enc.encode('c')];
 }
 const shared = shareSync(gen(), { budget: 16384 });
 const c1 = shared.pull();
 const c2 = shared.pull();
 const iterator1 = shared.pull()[Symbol.iterator]();
 const iterator2 = shared.pull()[Symbol.iterator]();
 const reason = new Error('sync cancel reason');

 iterator1.next();
 shared.cancel(reason);

 // c1 reads one item, then c2 cancels with a reason
 const iter1 = c1[Symbol.iterator]();
 const first = iter1.next();
 assert.strictEqual(first.done, false);
 assert.throws(() => iterator1.next(), (error) => error === reason);
 assert.throws(() => iterator2.next(), (error) => error === reason);
}

 shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = shareSync(fromSync('data'));
 const iterator = shared.pull()[Symbol.iterator]();

 // c1 was already iterating, it's now detached → done
 const next = iter1.next();
 assert.strictEqual(next.done, true);
 shared.cancel(reason);

 // c2 never started, also detached → done (not error)
 const batches = [];
 for (const batch of c2) {
 batches.push(batch);
 assert.throws(() => iterator.next(), (error) => error === reason);
 }
 assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
 testShareSyncCancel(),
 testShareSyncCancelMidIteration(),
 testShareSyncCancelWithReason(),
 testShareSyncCancelWithFalsyReason(),
 testShareSyncSourceError(),
 testShareSyncStringSource(),
]).then(common.mustCall());
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
stream: preserve falsy cancellation reasons#64705

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merged 1 commit into

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Aug 14, 2026
 Merged


stream: preserve falsy cancellation reasons
#64705
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10 changes: 6 additions & 4 deletions
lib/internal/streams/iter/broadcast.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
 #consumers = new SafeSet();
 #waiters = []; // Consumers with pending resolve (subset of #consumers)
 #ended = false;
 #error = null;
 #error;
 #cancelled = false;
 #options;
 #writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
 __proto__: null,
 next() {
 if (state.detached) {
 if (self.#error) return PromiseReject(self.#error);
 if (self.#error !== undefined) {
 return PromiseReject(self.#error);
 }
 return kDone;
 }

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
 { __proto__: null, done: false, value: chunk });
 }

 if (self.#error) {
 if (self.#error !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
 }

 [kAbort](reason) {
 if (this.#ended || this.#error) return;
 if (this.#ended || this.#error !== undefined) return;
 this.#error = reason;
 this.#ended = true;

Expand Down

26 changes: 14 additions & 12 deletions
lib/internal/streams/iter/share.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #pulling = false;
 #pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
 __proto__: null,
 [SymbolAsyncIterator]() {
 const getNext = async () => {
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#consumers.delete(state);
 throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
 // cursor must re-pull rather than terminating prematurely.
 for (;;) {
 if (state.detached) {
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
 if (self.#sourceExhausted) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
 if (shouldBuffer === null) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

 async #waitForBufferSpace() {
 while (this.#bufferedBytes >= this.#options.budget) {
 if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
 if (this.#cancelled ||
 this.#sourceError !== undefined ||
 this.#sourceExhausted) {
 return this.#cancelled ? null : true;
 }

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #cachedMinCursor = 0;
 #cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
 return {
 __proto__: null,
 next() {
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
 }
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#cancelled) {
 state.detached = true;
 self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

 self.#pullFromSource();

 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
Expand Down

16 changes: 8 additions & 8 deletions
test/parallel/test-stream-iter-broadcast-basic.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
 }, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
 const { broadcast: bc } = broadcast();
 const consumer = bc.push();
 const resultPromise = text(consumer).catch((err) => err);
 await new Promise((resolve) => setImmediate(resolve));
 bc.cancel(0);
 const result = await resultPromise;
 assert.strictEqual(result, 0);
 for (const reason of [0, '', false, null]) {
 const { broadcast: bc } = broadcast();
 const iterator = bc.push()[Symbol.asyncIterator]();

 bc.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

// Late-joining consumer should read from oldest buffered entry
Expand Down

12 changes: 12 additions & 0 deletions
test/parallel/test-stream-iter-share-async.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
 );
}

async function testShareCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = share(from('data'));
 const iterator = shared.pull()[Symbol.asyncIterator]();

 shared.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

async function testShareAbortSignal() {
 const ac = new AbortController();
 const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
 testShareCancel(),
 testShareCancelMidIteration(),
 testShareCancelWithReason(),
 testShareCancelWithFalsyReason(),
 testShareAbortSignal(),
 testShareAbortSignalWhileSourcePullPending(),
 testSharePullAbortSignalRejectsPendingNext(),
Expand Down

36 changes: 16 additions & 20 deletions
test/parallel/test-stream-iter-share-sync.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
 // When cancel(reason) is called, a consumer that hasn't started
 // iterating is already detached, so it sees done:true (not the error).
 // But a consumer that is mid-iteration when another consumer cancels
 // with a reason will see the error on the next pull after cancel.
 const enc = new TextEncoder();
 function* gen() {
 yield [enc.encode('a')];
 yield [enc.encode('b')];
 yield [enc.encode('c')];
 }
 const shared = shareSync(gen(), { budget: 16384 });
 const c1 = shared.pull();
 const c2 = shared.pull();
 const iterator1 = shared.pull()[Symbol.iterator]();
 const iterator2 = shared.pull()[Symbol.iterator]();
 const reason = new Error('sync cancel reason');

 iterator1.next();
 shared.cancel(reason);

 // c1 reads one item, then c2 cancels with a reason
 const iter1 = c1[Symbol.iterator]();
 const first = iter1.next();
 assert.strictEqual(first.done, false);
 assert.throws(() => iterator1.next(), (error) => error === reason);
 assert.throws(() => iterator2.next(), (error) => error === reason);
}

 shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = shareSync(fromSync('data'));
 const iterator = shared.pull()[Symbol.iterator]();

 // c1 was already iterating, it's now detached → done
 const next = iter1.next();
 assert.strictEqual(next.done, true);
 shared.cancel(reason);

 // c2 never started, also detached → done (not error)
 const batches = [];
 for (const batch of c2) {
 batches.push(batch);
 assert.throws(() => iterator.next(), (error) => error === reason);
 }
 assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
 testShareSyncCancel(),
 testShareSyncCancelMidIteration(),
 testShareSyncCancelWithReason(),
 testShareSyncCancelWithFalsyReason(),
 testShareSyncSourceError(),
 testShareSyncStringSource(),
]).then(common.mustCall());
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
stream: preserve falsy cancellation reasons#64705

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Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

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privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
Sign in
to your account

 Merged

nodejs-github-bot
merged 1 commit into

from

Aug 14, 2026
 Merged


stream: preserve falsy cancellation reasons
#64705
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10 changes: 6 additions & 4 deletions
lib/internal/streams/iter/broadcast.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
 #consumers = new SafeSet();
 #waiters = []; // Consumers with pending resolve (subset of #consumers)
 #ended = false;
 #error = null;
 #error;
 #cancelled = false;
 #options;
 #writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
 __proto__: null,
 next() {
 if (state.detached) {
 if (self.#error) return PromiseReject(self.#error);
 if (self.#error !== undefined) {
 return PromiseReject(self.#error);
 }
 return kDone;
 }

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
 { __proto__: null, done: false, value: chunk });
 }

 if (self.#error) {
 if (self.#error !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
 }

 [kAbort](reason) {
 if (this.#ended || this.#error) return;
 if (this.#ended || this.#error !== undefined) return;
 this.#error = reason;
 this.#ended = true;

Expand Down

26 changes: 14 additions & 12 deletions
lib/internal/streams/iter/share.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #pulling = false;
 #pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
 __proto__: null,
 [SymbolAsyncIterator]() {
 const getNext = async () => {
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#consumers.delete(state);
 throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
 // cursor must re-pull rather than terminating prematurely.
 for (;;) {
 if (state.detached) {
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
 if (self.#sourceExhausted) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
 if (shouldBuffer === null) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

 async #waitForBufferSpace() {
 while (this.#bufferedBytes >= this.#options.budget) {
 if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
 if (this.#cancelled ||
 this.#sourceError !== undefined ||
 this.#sourceExhausted) {
 return this.#cancelled ? null : true;
 }

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #cachedMinCursor = 0;
 #cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
 return {
 __proto__: null,
 next() {
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
 }
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#cancelled) {
 state.detached = true;
 self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

 self.#pullFromSource();

 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
Expand Down

16 changes: 8 additions & 8 deletions
test/parallel/test-stream-iter-broadcast-basic.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
 }, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
 const { broadcast: bc } = broadcast();
 const consumer = bc.push();
 const resultPromise = text(consumer).catch((err) => err);
 await new Promise((resolve) => setImmediate(resolve));
 bc.cancel(0);
 const result = await resultPromise;
 assert.strictEqual(result, 0);
 for (const reason of [0, '', false, null]) {
 const { broadcast: bc } = broadcast();
 const iterator = bc.push()[Symbol.asyncIterator]();

 bc.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

// Late-joining consumer should read from oldest buffered entry
Expand Down

12 changes: 12 additions & 0 deletions
test/parallel/test-stream-iter-share-async.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
 );
}

async function testShareCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = share(from('data'));
 const iterator = shared.pull()[Symbol.asyncIterator]();

 shared.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

async function testShareAbortSignal() {
 const ac = new AbortController();
 const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
 testShareCancel(),
 testShareCancelMidIteration(),
 testShareCancelWithReason(),
 testShareCancelWithFalsyReason(),
 testShareAbortSignal(),
 testShareAbortSignalWhileSourcePullPending(),
 testSharePullAbortSignalRejectsPendingNext(),
Expand Down

36 changes: 16 additions & 20 deletions
test/parallel/test-stream-iter-share-sync.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
 // When cancel(reason) is called, a consumer that hasn't started
 // iterating is already detached, so it sees done:true (not the error).
 // But a consumer that is mid-iteration when another consumer cancels
 // with a reason will see the error on the next pull after cancel.
 const enc = new TextEncoder();
 function* gen() {
 yield [enc.encode('a')];
 yield [enc.encode('b')];
 yield [enc.encode('c')];
 }
 const shared = shareSync(gen(), { budget: 16384 });
 const c1 = shared.pull();
 const c2 = shared.pull();
 const iterator1 = shared.pull()[Symbol.iterator]();
 const iterator2 = shared.pull()[Symbol.iterator]();
 const reason = new Error('sync cancel reason');

 iterator1.next();
 shared.cancel(reason);

 // c1 reads one item, then c2 cancels with a reason
 const iter1 = c1[Symbol.iterator]();
 const first = iter1.next();
 assert.strictEqual(first.done, false);
 assert.throws(() => iterator1.next(), (error) => error === reason);
 assert.throws(() => iterator2.next(), (error) => error === reason);
}

 shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = shareSync(fromSync('data'));
 const iterator = shared.pull()[Symbol.iterator]();

 // c1 was already iterating, it's now detached → done
 const next = iter1.next();
 assert.strictEqual(next.done, true);
 shared.cancel(reason);

 // c2 never started, also detached → done (not error)
 const batches = [];
 for (const batch of c2) {
 batches.push(batch);
 assert.throws(() => iterator.next(), (error) => error === reason);
 }
 assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
 testShareSyncCancel(),
 testShareSyncCancelMidIteration(),
 testShareSyncCancelWithReason(),
 testShareSyncCancelWithFalsyReason(),
 testShareSyncSourceError(),
 testShareSyncStringSource(),
]).then(common.mustCall());
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

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stream: preserve falsy cancellation reasons#64705

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merged 1 commit into

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Aug 14, 2026
 Merged


stream: preserve falsy cancellation reasons
#64705
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10 changes: 6 additions & 4 deletions
lib/internal/streams/iter/broadcast.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
 #consumers = new SafeSet();
 #waiters = []; // Consumers with pending resolve (subset of #consumers)
 #ended = false;
 #error = null;
 #error;
 #cancelled = false;
 #options;
 #writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
 __proto__: null,
 next() {
 if (state.detached) {
 if (self.#error) return PromiseReject(self.#error);
 if (self.#error !== undefined) {
 return PromiseReject(self.#error);
 }
 return kDone;
 }

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
 { __proto__: null, done: false, value: chunk });
 }

 if (self.#error) {
 if (self.#error !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
 }

 [kAbort](reason) {
 if (this.#ended || this.#error) return;
 if (this.#ended || this.#error !== undefined) return;
 this.#error = reason;
 this.#ended = true;

Expand Down

26 changes: 14 additions & 12 deletions
lib/internal/streams/iter/share.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #pulling = false;
 #pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
 __proto__: null,
 [SymbolAsyncIterator]() {
 const getNext = async () => {
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#consumers.delete(state);
 throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
 // cursor must re-pull rather than terminating prematurely.
 for (;;) {
 if (state.detached) {
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
 if (self.#sourceExhausted) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
 if (shouldBuffer === null) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

 async #waitForBufferSpace() {
 while (this.#bufferedBytes >= this.#options.budget) {
 if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
 if (this.#cancelled ||
 this.#sourceError !== undefined ||
 this.#sourceExhausted) {
 return this.#cancelled ? null : true;
 }

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #cachedMinCursor = 0;
 #cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
 return {
 __proto__: null,
 next() {
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
 }
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#cancelled) {
 state.detached = true;
 self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

 self.#pullFromSource();

 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
Expand Down

16 changes: 8 additions & 8 deletions
test/parallel/test-stream-iter-broadcast-basic.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
 }, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
 const { broadcast: bc } = broadcast();
 const consumer = bc.push();
 const resultPromise = text(consumer).catch((err) => err);
 await new Promise((resolve) => setImmediate(resolve));
 bc.cancel(0);
 const result = await resultPromise;
 assert.strictEqual(result, 0);
 for (const reason of [0, '', false, null]) {
 const { broadcast: bc } = broadcast();
 const iterator = bc.push()[Symbol.asyncIterator]();

 bc.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

// Late-joining consumer should read from oldest buffered entry
Expand Down

12 changes: 12 additions & 0 deletions
test/parallel/test-stream-iter-share-async.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
 );
}

async function testShareCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = share(from('data'));
 const iterator = shared.pull()[Symbol.asyncIterator]();

 shared.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

async function testShareAbortSignal() {
 const ac = new AbortController();
 const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
 testShareCancel(),
 testShareCancelMidIteration(),
 testShareCancelWithReason(),
 testShareCancelWithFalsyReason(),
 testShareAbortSignal(),
 testShareAbortSignalWhileSourcePullPending(),
 testSharePullAbortSignalRejectsPendingNext(),
Expand Down

36 changes: 16 additions & 20 deletions
test/parallel/test-stream-iter-share-sync.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
 // When cancel(reason) is called, a consumer that hasn't started
 // iterating is already detached, so it sees done:true (not the error).
 // But a consumer that is mid-iteration when another consumer cancels
 // with a reason will see the error on the next pull after cancel.
 const enc = new TextEncoder();
 function* gen() {
 yield [enc.encode('a')];
 yield [enc.encode('b')];
 yield [enc.encode('c')];
 }
 const shared = shareSync(gen(), { budget: 16384 });
 const c1 = shared.pull();
 const c2 = shared.pull();
 const iterator1 = shared.pull()[Symbol.iterator]();
 const iterator2 = shared.pull()[Symbol.iterator]();
 const reason = new Error('sync cancel reason');

 iterator1.next();
 shared.cancel(reason);

 // c1 reads one item, then c2 cancels with a reason
 const iter1 = c1[Symbol.iterator]();
 const first = iter1.next();
 assert.strictEqual(first.done, false);
 assert.throws(() => iterator1.next(), (error) => error === reason);
 assert.throws(() => iterator2.next(), (error) => error === reason);
}

 shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = shareSync(fromSync('data'));
 const iterator = shared.pull()[Symbol.iterator]();

 // c1 was already iterating, it's now detached → done
 const next = iter1.next();
 assert.strictEqual(next.done, true);
 shared.cancel(reason);

 // c2 never started, also detached → done (not error)
 const batches = [];
 for (const batch of c2) {
 batches.push(batch);
 assert.throws(() => iterator.next(), (error) => error === reason);
 }
 assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
 testShareSyncCancel(),
 testShareSyncCancelMidIteration(),
 testShareSyncCancelWithReason(),
 testShareSyncCancelWithFalsyReason(),
 testShareSyncSourceError(),
 testShareSyncStringSource(),
]).then(common.mustCall());
Loading

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
stream: preserve falsy cancellation reasons#64705

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privacy statement. We’ll occasionally send you account related emails.

Already on GitHub?
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to your account

 Merged

nodejs-github-bot
merged 1 commit into

from

Aug 14, 2026
 Merged


stream: preserve falsy cancellation reasons
#64705
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10 changes: 6 additions & 4 deletions
lib/internal/streams/iter/broadcast.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
 #consumers = new SafeSet();
 #waiters = []; // Consumers with pending resolve (subset of #consumers)
 #ended = false;
 #error = null;
 #error;
 #cancelled = false;
 #options;
 #writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
 __proto__: null,
 next() {
 if (state.detached) {
 if (self.#error) return PromiseReject(self.#error);
 if (self.#error !== undefined) {
 return PromiseReject(self.#error);
 }
 return kDone;
 }

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
 { __proto__: null, done: false, value: chunk });
 }

 if (self.#error) {
 if (self.#error !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
 }

 [kAbort](reason) {
 if (this.#ended || this.#error) return;
 if (this.#ended || this.#error !== undefined) return;
 this.#error = reason;
 this.#ended = true;

Expand Down

26 changes: 14 additions & 12 deletions
lib/internal/streams/iter/share.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #pulling = false;
 #pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
 __proto__: null,
 [SymbolAsyncIterator]() {
 const getNext = async () => {
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#consumers.delete(state);
 throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
 // cursor must re-pull rather than terminating prematurely.
 for (;;) {
 if (state.detached) {
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
 if (self.#sourceExhausted) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
 if (shouldBuffer === null) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

 async #waitForBufferSpace() {
 while (this.#bufferedBytes >= this.#options.budget) {
 if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
 if (this.#cancelled ||
 this.#sourceError !== undefined ||
 this.#sourceExhausted) {
 return this.#cancelled ? null : true;
 }

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #cachedMinCursor = 0;
 #cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
 return {
 __proto__: null,
 next() {
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
 }
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#cancelled) {
 state.detached = true;
 self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

 self.#pullFromSource();

 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
Expand Down

16 changes: 8 additions & 8 deletions
test/parallel/test-stream-iter-broadcast-basic.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
 }, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
 const { broadcast: bc } = broadcast();
 const consumer = bc.push();
 const resultPromise = text(consumer).catch((err) => err);
 await new Promise((resolve) => setImmediate(resolve));
 bc.cancel(0);
 const result = await resultPromise;
 assert.strictEqual(result, 0);
 for (const reason of [0, '', false, null]) {
 const { broadcast: bc } = broadcast();
 const iterator = bc.push()[Symbol.asyncIterator]();

 bc.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

// Late-joining consumer should read from oldest buffered entry
Expand Down

12 changes: 12 additions & 0 deletions
test/parallel/test-stream-iter-share-async.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
 );
}

async function testShareCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = share(from('data'));
 const iterator = shared.pull()[Symbol.asyncIterator]();

 shared.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

async function testShareAbortSignal() {
 const ac = new AbortController();
 const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
 testShareCancel(),
 testShareCancelMidIteration(),
 testShareCancelWithReason(),
 testShareCancelWithFalsyReason(),
 testShareAbortSignal(),
 testShareAbortSignalWhileSourcePullPending(),
 testSharePullAbortSignalRejectsPendingNext(),
Expand Down

36 changes: 16 additions & 20 deletions
test/parallel/test-stream-iter-share-sync.js

View file


Open in desktop

Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
 // When cancel(reason) is called, a consumer that hasn't started
 // iterating is already detached, so it sees done:true (not the error).
 // But a consumer that is mid-iteration when another consumer cancels
 // with a reason will see the error on the next pull after cancel.
 const enc = new TextEncoder();
 function* gen() {
 yield [enc.encode('a')];
 yield [enc.encode('b')];
 yield [enc.encode('c')];
 }
 const shared = shareSync(gen(), { budget: 16384 });
 const c1 = shared.pull();
 const c2 = shared.pull();
 const iterator1 = shared.pull()[Symbol.iterator]();
 const iterator2 = shared.pull()[Symbol.iterator]();
 const reason = new Error('sync cancel reason');

 iterator1.next();
 shared.cancel(reason);

 // c1 reads one item, then c2 cancels with a reason
 const iter1 = c1[Symbol.iterator]();
 const first = iter1.next();
 assert.strictEqual(first.done, false);
 assert.throws(() => iterator1.next(), (error) => error === reason);
 assert.throws(() => iterator2.next(), (error) => error === reason);
}

 shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = shareSync(fromSync('data'));
 const iterator = shared.pull()[Symbol.iterator]();

 // c1 was already iterating, it's now detached → done
 const next = iter1.next();
 assert.strictEqual(next.done, true);
 shared.cancel(reason);

 // c2 never started, also detached → done (not error)
 const batches = [];
 for (const batch of c2) {
 batches.push(batch);
 assert.throws(() => iterator.next(), (error) => error === reason);
 }
 assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
 testShareSyncCancel(),
 testShareSyncCancelMidIteration(),
 testShareSyncCancelWithReason(),
 testShareSyncCancelWithFalsyReason(),
 testShareSyncSourceError(),
 testShareSyncStringSource(),
]).then(common.mustCall());
Loading

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

Skip to content
stream: preserve falsy cancellation reasons#64705

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 Merged

nodejs-github-bot
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Aug 14, 2026
 Merged


stream: preserve falsy cancellation reasons
#64705
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10 changes: 6 additions & 4 deletions
lib/internal/streams/iter/broadcast.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -88,7 +88,7 @@ class BroadcastImpl {
 #consumers = new SafeSet();
 #waiters = []; // Consumers with pending resolve (subset of #consumers)
 #ended = false;
 #error = null;
 #error;
 #cancelled = false;
 #options;
 #writer = null;
Expand DownExpand Up@@ -177,7 +177,9 @@ class BroadcastImpl {
 __proto__: null,
 next() {
 if (state.detached) {
 if (self.#error) return PromiseReject(self.#error);
 if (self.#error !== undefined) {
 return PromiseReject(self.#error);
 }
 return kDone;
 }

Expand All@@ -194,7 +196,7 @@ class BroadcastImpl {
 { __proto__: null, done: false, value: chunk });
 }

 if (self.#error) {
 if (self.#error !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 return PromiseReject(self.#error);
Expand DownExpand Up@@ -344,7 +346,7 @@ class BroadcastImpl {
 }

 [kAbort](reason) {
 if (this.#ended || this.#error) return;
 if (this.#ended || this.#error !== undefined) return;
 this.#error = reason;
 this.#ended = true;

Expand Down

26 changes: 14 additions & 12 deletions
lib/internal/streams/iter/share.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -73,7 +73,7 @@ class ShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #pulling = false;
 #pullWaiters = [];
Expand DownExpand Up@@ -129,7 +129,7 @@ class ShareImpl {
 __proto__: null,
 [SymbolAsyncIterator]() {
 const getNext = async () => {
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#consumers.delete(state);
 throw self.#sourceError;
Expand All@@ -141,7 +141,7 @@ class ShareImpl {
 // cursor must re-pull rather than terminating prematurely.
 for (;;) {
 if (state.detached) {
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -167,7 +167,7 @@ class ShareImpl {
 if (self.#sourceExhausted) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand All@@ -176,7 +176,7 @@ class ShareImpl {
 if (shouldBuffer === null) {
 state.detached = true;
 self.#deleteConsumer(state);
 if (self.#sourceError) throw self.#sourceError;
 if (self.#sourceError !== undefined) throw self.#sourceError;
 return { __proto__: null, done: true, value: undefined };
 }

Expand DownExpand Up@@ -260,7 +260,9 @@ class ShareImpl {

 async #waitForBufferSpace() {
 while (this.#bufferedBytes >= this.#options.budget) {
 if (this.#cancelled || this.#sourceError || this.#sourceExhausted) {
 if (this.#cancelled ||
 this.#sourceError !== undefined ||
 this.#sourceExhausted) {
 return this.#cancelled ? null : true;
 }

Expand DownExpand Up@@ -418,7 +420,7 @@ class SyncShareImpl {
 #consumers = new SafeSet();
 #sourceIterator = null;
 #sourceExhausted = false;
 #sourceError = null;
 #sourceError;
 #cancelled = false;
 #cachedMinCursor = 0;
 #cachedMinCursorConsumers = 0;
Expand DownExpand Up@@ -467,14 +469,14 @@ class SyncShareImpl {
 return {
 __proto__: null,
 next() {
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
 }
 if (state.detached) {
 return { __proto__: null, done: true, value: undefined };
 }
 if (self.#cancelled) {
 state.detached = true;
 self.#deleteConsumer(state);
Expand DownExpand Up@@ -535,7 +537,7 @@ class SyncShareImpl {

 self.#pullFromSource();

 if (self.#sourceError) {
 if (self.#sourceError !== undefined) {
 state.detached = true;
 self.#deleteConsumer(state);
 throw self.#sourceError;
Expand Down

16 changes: 8 additions & 8 deletions
test/parallel/test-stream-iter-broadcast-basic.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -260,15 +260,15 @@ async function testWriterFailIdempotent() {
 }, { message: 'fail!' });
}

// cancel() with falsy reason (0, "", false) should still treat as error
async function testCancelWithFalsyReason() {
 const { broadcast: bc } = broadcast();
 const consumer = bc.push();
 const resultPromise = text(consumer).catch((err) => err);
 await new Promise((resolve) => setImmediate(resolve));
 bc.cancel(0);
 const result = await resultPromise;
 assert.strictEqual(result, 0);
 for (const reason of [0, '', false, null]) {
 const { broadcast: bc } = broadcast();
 const iterator = bc.push()[Symbol.asyncIterator]();

 bc.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

// Late-joining consumer should read from oldest buffered entry
Expand Down

12 changes: 12 additions & 0 deletions
test/parallel/test-stream-iter-share-async.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -132,6 +132,17 @@ async function testShareCancelWithReason() {
 );
}

async function testShareCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = share(from('data'));
 const iterator = shared.pull()[Symbol.asyncIterator]();

 shared.cancel(reason);

 await assert.rejects(iterator.next(), (error) => error === reason);
 }
}

async function testShareAbortSignal() {
 const ac = new AbortController();
 const reason = new Error('share aborted');
Expand DownExpand Up@@ -357,6 +368,7 @@ Promise.all([
 testShareCancel(),
 testShareCancelMidIteration(),
 testShareCancelWithReason(),
 testShareCancelWithFalsyReason(),
 testShareAbortSignal(),
 testShareAbortSignalWhileSourcePullPending(),
 testSharePullAbortSignalRejectsPendingNext(),
Expand Down

36 changes: 16 additions & 20 deletions
test/parallel/test-stream-iter-share-sync.js

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Original file line numberDiff line numberDiff line change
Expand Up@@ -87,37 +87,32 @@ function testShareSyncCancelMidIteration() {
}

function testShareSyncCancelWithReason() {
 // When cancel(reason) is called, a consumer that hasn't started
 // iterating is already detached, so it sees done:true (not the error).
 // But a consumer that is mid-iteration when another consumer cancels
 // with a reason will see the error on the next pull after cancel.
 const enc = new TextEncoder();
 function* gen() {
 yield [enc.encode('a')];
 yield [enc.encode('b')];
 yield [enc.encode('c')];
 }
 const shared = shareSync(gen(), { budget: 16384 });
 const c1 = shared.pull();
 const c2 = shared.pull();
 const iterator1 = shared.pull()[Symbol.iterator]();
 const iterator2 = shared.pull()[Symbol.iterator]();
 const reason = new Error('sync cancel reason');

 iterator1.next();
 shared.cancel(reason);

 // c1 reads one item, then c2 cancels with a reason
 const iter1 = c1[Symbol.iterator]();
 const first = iter1.next();
 assert.strictEqual(first.done, false);
 assert.throws(() => iterator1.next(), (error) => error === reason);
 assert.throws(() => iterator2.next(), (error) => error === reason);
}

 shared.cancel(new Error('sync cancel reason'));
function testShareSyncCancelWithFalsyReason() {
 for (const reason of [0, '', false, null]) {
 const shared = shareSync(fromSync('data'));
 const iterator = shared.pull()[Symbol.iterator]();

 // c1 was already iterating, it's now detached → done
 const next = iter1.next();
 assert.strictEqual(next.done, true);
 shared.cancel(reason);

 // c2 never started, also detached → done (not error)
 const batches = [];
 for (const batch of c2) {
 batches.push(batch);
 assert.throws(() => iterator.next(), (error) => error === reason);
 }
 assert.strictEqual(batches.length, 0);
}

// =============================================================================
Expand DownExpand Up@@ -157,6 +152,7 @@ Promise.all([
 testShareSyncCancel(),
 testShareSyncCancelMidIteration(),
 testShareSyncCancelWithReason(),
 testShareSyncCancelWithFalsyReason(),
 testShareSyncSourceError(),
 testShareSyncStringSource(),
]).then(common.mustCall());
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