René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"`process.finalization` removes extra refs during cleanup","articleBody":"### Version\n\nmain\n\n### Platform\n\n```text\nmacOS 26.5.0\n```\n\n### Subsystem\n\nprocess\n\n### What steps will reproduce the bug?\n\n```js\nimport process from 'node:process';\nimport { setImmediate } from 'node:timers/promises';\n\nconst kept = [];\n\nfunction onFinalize(ref) {\n  console.log(`finalized: ${ref.name}`);\n}\n\nfunction setup() {\n  const first = { name: 'first' };\n  let collected = { name: 'collected' };\n  const third = { name: 'third' };\n\n  kept.push(first, third);\n\n  process.finalization.register(first, onFinalize);\n  process.finalization.register(collected, onFinalize);\n  process.finalization.register(third, onFinalize);\n\n  collected = null;\n}\n\nsetup();\n\n// Give V8 a few chances to collect `collected` and run the\n// FinalizationRegistry cleanup before process exit.\nfor (let i = 0; i \u003c 10; i++) {\n  gc();\n  await setImmediate();\n}\n\nconsole.log('expected: finalized: first');\nconsole.log('expected: finalized: third');\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\n```console\nexpected: finalized: first\nexpected: finalized: third\nfinalized: first\nfinalized: third\n```\n\nBoth `first` and `third` are strongly reachable through `kept`, so both should remain registered and run their finalization callbacks during process exit.\n\n### What do you see instead?\n\n```console\nexpected: finalized: first\nexpected: finalized: third\nfinalized: first\n```\n\nAfter `collected` is garbage-collected, cleanup removes its ref and also removes `third` because `splice(1, 2)` deletes two entries. As a result, `third` is still alive but its exit callback is skipped.\n\n### Additional information\n\nNoticed while working on https://github.com/nodejs/node/pull/64085\n\nThe docs for [`process.finalization.register(ref, callback)`](https://nodejs.org/api/process.html#processfinalizationregisterref-callback) say that it \"registers a callback to be called when the process emits the `exit` event if the `ref` object was not garbage collected.\"","author":{"url":"https://github.com/trivikr","@type":"Person","name":"trivikr"},"datePublished":"2026-06-23T05:33:29.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/64086/node/issues/64086"}