René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Errors in composed streams hang since Node 22.5","articleBody":"### Version\n\n22.20.0\n\n### Platform\n\n```text\nDarwin Patricks-Laptop.local 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:29 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6000 arm64\n```\n\n### Subsystem\n\nstreams\n\n### What steps will reproduce the bug?\n\nAssuming a `file.txt` on disk that contains random text (e.g. `hello`), the following script will appropriately hit the catch block in Node 22.4.1 but not in Node versions after (including current LTS 22.20.0). I believe it is related to this change: https://github.com/nodejs/node/pull/53462\n\n```js\nimport { createReadStream } from \"node:fs\";\n\nconst fileStream = createReadStream(\"./file.txt\", {\n  encoding: \"utf8\",\n});\n\nconst composedStreamOne = async function* (objectStream) {\n  for await (const obj of objectStream) {\n    throw new Error(\"Intentional error in composedStreamOne\");\n  }\n};\n\nconst composedStreamTwo = async function* (objectStream) {\n  for await (const obj of objectStream) {\n    yield obj + \"goodbye\";\n  }\n};\n\nconst composed = fileStream\n  .compose(composedStreamOne)\n  .compose(composedStreamTwo);\n\ntry {\n  for await (const text of composed) {\n    console.log(\"String is:\", text);\n  }\n} catch (err) {\n  console.error(\"Caught error:\", err.message);\n}\n```\n\nIn Node 22.4.1 we get:\n\n```\nnode -v \u0026\u0026 node compose.mjs\nv22.4.1\nCaught error: Intentional error in composedStreamOne\n```\n\nIn Node 22.5.0+ we get:\n\n```\nnode -v \u0026\u0026 node compose.mjs\nv22.5.0\nWarning: Detected unsettled top-level await at file:///Users/patrickshipe/projects/compose-bug/compose.mjs:24\n  for await (const text of composed) {\n```\n\n### How often does it reproduce? Is there a required condition?\n\nIt will reproduce 100% of the time when composing streams like this.\n\n### What is the expected behavior? Why is that the expected behavior?\n\nThe expected behavior is that the composed stream will correctly bubble up an error in any of the constituent streams.\n\n### What do you see instead?\n\nThe script will never complete, or fail on unsettled top-level await if at the top level.\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/patrickshipe","@type":"Person","name":"patrickshipe"},"datePublished":"2025-10-01T12:37:09.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/60083/node/issues/60083"}