René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"stream/iter: falsy cancellation reasons become clean EOF in broadcast and share","articleBody":"### Version\n\nmain\n\n### Platform\n\n```text\nmacOS 26.5.2\n```\n\n### Subsystem\n\nstream\n\n### What steps will reproduce the bug?\n\n```js\nimport { broadcast, share, shareSync } from 'node:stream/iter';\n\nconst reasons = [0, '', false, null];\n\nasync function run(name, make) {\n  for (const reason of reasons) {\n    const { stream, iterator } = make();\n    stream.cancel(reason);\n\n    try {\n      console.log(name, JSON.stringify(reason), await iterator.next());\n    } catch (error) {\n      console.log(name, JSON.stringify(reason), 'rejected:', error);\n    }\n  }\n}\n\nawait run('broadcast', () => {\n  const { broadcast: stream } = broadcast();\n  return {\n    stream,\n    iterator: stream.push()[Symbol.asyncIterator](),\n  };\n});\n\nawait run('share', () => {\n  const stream = share([]);\n  return {\n    stream,\n    iterator: stream.pull()[Symbol.asyncIterator](),\n  };\n});\n\nawait run('shareSync', () => {\n  const stream = shareSync([]);\n  return {\n    stream,\n    iterator: stream.pull()[Symbol.iterator](),\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\nasync `next()` should reject—and sync `next()` should throw—with the exact supplied reason, consistent with [§13.1.4 `Broadcast.cancel()`](https://stream-iter.jasnell.me/#broadcast-cancel) and the corresponding [§13.2.4 `Share.cancel()`](https://stream-iter.jasnell.me/#share-cancel).\n\n> If reason is provided, each consumer sees it as an error; otherwise they see clean completion.\n\n### What do you see instead?\n\n```console\nbroadcast 0 { done: true, value: undefined }\nbroadcast \"\" { done: true, value: undefined }\nbroadcast false { done: true, value: undefined }\nbroadcast null { done: true, value: undefined }\nshare 0 { done: true, value: undefined }\nshare \"\" { done: true, value: undefined }\nshare false { done: true, value: undefined }\nshare null { done: true, value: undefined }\nshareSync 0 { done: true, value: undefined }\nshareSync \"\" { done: true, value: undefined }\nshareSync false { done: true, value: undefined }\nshareSync null { done: true, value: undefined }\n```\n\nevery falsy reason is converted into clean completion for consumers that had not called `next()` before cancellation.\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/trivikr","@type":"Person","name":"trivikr"},"datePublished":"2026-07-24T04:28:44Z","url":"https://github.com/nodejs/node/issues/64704"}