Know when a process ended due to the `child_process.spawn()` `timeout` option
What is the problem this feature will solve?
When a process ends due to the timeout
option of child_process.spawn()
, there is no way to know whether that termination was due to the timeout. A SIGTERM
is sent to the process, but that's pretty much it.
import {spawn} from 'node:child_process'
const childProcess = spawn('node', ['-e', 'setTimeout(() => {}, 1e7)'], {
timeout: 2e3,
stdio: 'inherit', // no stdout/stderr
})
childProcess.on('exit', (exitCode, signal) => {
console.log({exitCode, signal}) // { exitCode: null, signal: 'SIGTERM' }
})
This makes debugging harder. Some users might be left wondering why the process ended if they don't pay attention to the timeout
option.
What is the feature you are proposing to solve the problem?
Having a way to know whether the process ended due to the timeout
option. Any implementation would work. Some potential ideas:
-
timeout
event onchildProcess
- third boolean argument
timedOut
passed to theexit
event - emit an
error
event witherror.code: 'ETIMEDOUT'
onchildProcess
. This is a breaking change since many users are currently listening forerror
events, so would probably not be a good idea. childProcess.timedOut = true
-
childProcess.timedOut()
returning a boolean
What alternatives have you considered?
One could possibly set a manual timeout like the following.
let timedOut = false
setTimeout(() => {
timedOut = true
}, 2e3)
However, it defeats some of the convenience of the timeout
option, since that one might as well call childProcess.kill()
themselves then. Also, it is slightly unreliable since an unrelated SIGTERM
could theoretically have been sent at the exact same time.