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SyntaxError in node:perf_hooks documentation #60368
Description
Affected URL(s)
https://nodejs.org/api/perf_hooks.html#performanceeventlooputilizationutilization1-utilization2
Description of the problem
I saved the example code in a file test.mjs:
import { eventLoopUtilization } from 'node:perf_hooks';
import { spawnSync } from 'node:child_process';
setImmediate(() => {
const elu = eventLoopUtilization();
spawnSync('sleep', ['5']);
console.log(eventLoopUtilization(elu).utilization);
});Upon running node test.mjs, an exception is thrown:
SyntaxError: The requested module 'node:perf_hooks' does not provide an export named 'eventLoopUtilization'
However, importing performance works:
import { performance } from 'node:perf_hooks';
import { spawnSync } from 'node:child_process';
setImmediate(() => {
const elu = performance.eventLoopUtilization();
spawnSync('sleep', ['5']);
console.log(performance.eventLoopUtilization(elu).utilization);
});
Activity
marco-ippolito commentedon Oct 22, 2025
yes
eventLoopUtilizationis not exported directly, we should fix the documentationlegendecas commentedon Oct 22, 2025
I think there is no reason that we should expose
eventLoopUtilizationon Webperformanceobject. The function can be used standalone without dependencies on theperformanceAPI. We should expose it on theperf_hooksmodule directly: #60370felixcamilo commentedon Oct 24, 2025
the EventLoopUtilization() can not be imported because it is not exported in the other hand performance object is actually exported explicitly so all you need to do is extracting the EventLoopUtilization() method from the performance object and the issue will be solved
perf_hooks: move non-standard performance properties to perf_hooks
perf_hooks: move non-standard performance properties to perf_hooks
perf_hooks: move non-standard performance properties to perf_hooks
perf_hooks: move non-standard performance properties to perf_hooks
perf_hooks: move non-standard performance properties to perf_hooks
perf_hooks: move non-standard performance properties to perf_hooks