René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"stream/iter: Broadcast and Share leak consumers for invalid or pre-aborted signals","articleBody":"### Version\n\nmain\n\n### Platform\n\n```text\nN/A\n```\n\n### Subsystem\n\nstream\n\n### What steps will reproduce the bug?\n\n```js\nimport { broadcast, share, from } from 'node:stream/iter';\n\nconst cases = [\n  ['Broadcast', () => {\n    const { broadcast: bc } = broadcast();\n    return [bc, (options) => bc.push(options)];\n  }],\n  ['Share', () => {\n    const shared = share(from('x'));\n    return [shared, (options) => shared.pull(options)];\n  }],\n];\n\nfor (const [name, make] of cases) {\n  let [owner, consume] = make();\n\n  try {\n    consume({ signal: {} });\n  } catch (error) {\n    console.log(name, 'invalid signal:', error.code,\n                'consumerCount:', owner.consumerCount);\n  }\n\n  [owner, consume] = make();\n\n  const controller = new AbortController();\n  controller.abort(new Error('already aborted'));\n\n  const iterator =\n    consume({ signal: controller.signal })[Symbol.asyncIterator]();\n\n  try {\n    await iterator.next();\n  } catch (error) {\n    console.log(name, 'pre-aborted signal:', error.message,\n                'consumerCount:', owner.consumerCount);\n  }\n}\n```\n\n### How often does it reproduce? Is there a required condition?\n\nAlways\n\n### What is the expected behavior? Why is that the expected behavior?\n\nSignal validation or pre-abort handling should not register a consumer - or should immediately detach it - so `consumerCount` remains `0`.\n\nAs per [§13.1.3, Broadcast.push()](https://iter-streams.proposal.wintertc.org/#broadcast-push) and [§13.2.3, Share.pull()](https://iter-streams.proposal.wintertc.org/#share-pull)\n> On break/error, abort pipelineController and detach the cursor.\n\n### What do you see instead?\n\n```console\nBroadcast invalid signal: ERR_INVALID_ARG_TYPE consumerCount: 1\nBroadcast pre-aborted signal: already aborted consumerCount: 1\nShare invalid signal: ERR_INVALID_ARG_TYPE consumerCount: 1\nShare pre-aborted signal: already aborted consumerCount: 1\n```\n\nPassing an invalid or already-aborted signal throws or rejects, but leaves an inaccessible consumer registered with `consumerCount === 1`, potentially causing permanent backpressure.\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/trivikr","@type":"Person","name":"trivikr"},"datePublished":"2026-08-15T04:45:55Z","url":"https://github.com/nodejs/node/issues/65298"}