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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Calling `socket.destroy()` causes unhandled error in v12.16.3","articleBody":"* **Version**: v12.16.3\r\n* **Platform**: Linux 73659abd8e3f 4.19.76-linuxkit #1 SMP Thu Oct 17 19:31:58 UTC 2019 x86_64 GNU/Linux\r\n* **Subsystem**: _http_agent, _http_client\r\n\r\n### What steps will reproduce the bug?\r\n\r\n```javascript\r\nconst http = require('http')\r\nconst { host = '127.0.0.1', port = '8080' } = process.env\r\n\r\nhttp\r\n  .createServer((_, res) => {\r\n    res.end('data')\r\n  })\r\n  .listen(port, () => {\r\n    const request = http\r\n      .request({\r\n        host,\r\n        port,\r\n        headers: { 'Connection': 'keep-alive' }\r\n      }, response => {\r\n        response\r\n          .on('data', () => {})\r\n          .on('end', () => {})\r\n      })\r\n      .end()\r\n    setTimeout(() => {\r\n      request.socket.destroy('Some error') // this line causes the error\r\n    }, 500)\r\n  })\r\n\r\n```\r\n### How often does it reproduce? Is there a required condition?\r\n\r\nIt is reproduced 100% when running the code snippet above with node v12.16.3.\r\n\r\n### What is the expected behavior?\r\n\r\nThe behavior is inconsistent between node v12.16.2 and v12.16.3. I suppose, it would be ok in a next major-version. But, as it is a patch-version release, the error should not be thrown.\r\n\r\n### What do you see instead?\r\n\r\n```\r\nevents.js:301\r\n    throw err; // Unhandled 'error' event\r\n    ^\r\n\r\nError [ERR_UNHANDLED_ERROR]: Unhandled error. ('Some error')\r\n    at Socket.emit (events.js:299:17)\r\n    at emitErrorNT (internal/streams/destroy.js:92:8)\r\n    at processTicksAndRejections (internal/process/task_queues.js:84:21) {\r\n  code: 'ERR_UNHANDLED_ERROR',\r\n  context: 'Some error'\r\n}\r\n```\r\n\r\n### Additional information\r\n\r\nLooks like the problem is caused by this commit https://github.com/nodejs/node/commit/225ddd5f425313908cf53d5d29fe746612d31e4c, it's exactly what @ronag described [here](https://github.com/nodejs/node/commit/225ddd5f425313908cf53d5d29fe746612d31e4c#diff-e3bc37430eb078ccbafe3aa3b570c91aR619). The socket has no `'error'` event handler, so [unhandled error is thrown](https://github.com/nodejs/node/blob/225ddd5f425313908cf53d5d29fe746612d31e4c/lib/events.js#L287), which can only be caught with `process.on`. Otherwise the process crashes.\r\n\r\nI'm not sure if it's a heavy breaking change or the commit I mentioned should be reverted, as it can easily be fixed by adding an `'error'` event handler to a socket. But it definitely caused me an hour or two of happy debug.\r\n\r\nPlease let me know if I can help with those todos in `_http_client.js`.","author":{"url":"https://github.com/pkozemirov","@type":"Person","name":"pkozemirov"},"datePublished":"2020-05-16T12:29:03Z","url":"https://github.com/nodejs/node/issues/33434"}