test: fix incorrect calculation in test-perf-hooks.js

After https://redirect.github.com/nodejs/node/pull/46588, Date.now() - performance.timeOrigin and process.uptime() are no longer similar - the former measures uptime from process initilaization, while the latter measures uptime from the main context initialization. Account for the differences in the test. PR-URL: #60271 Refs: https://github.com/nodejs/reliability/blob/main/reports/2025-10-15.md Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: Ulises Gascón <ulisesgascongonzalez@gmail.com>

Author: joyeecheung

test/sequential/test-perf-hooks.js

@@ -28,15 +28,10 @@ const epsilon = 50;
 {
  const uptime1 = Date.now() - performance.timeOrigin;
  const uptime2 = performance.now();
- const uptime3 = process.uptime() * 1000;
  assert(Math.abs(uptime1 - uptime2) < epsilon,
  `Date.now() - performance.timeOrigin (${uptime1}) - ` +
  `performance.now() (${uptime2}) = ` +
  `${uptime1 - uptime2} >= +- ${epsilon}`);
- assert(Math.abs(uptime1 - uptime3) < epsilon,
- `Date.now() - performance.timeOrigin (${uptime1}) - ` +
- `process.uptime() * 1000 (${uptime3}) = ` +
- `${uptime1 - uptime3} >= +- ${epsilon}`);
 }
 
 assert.strictEqual(performance.nodeTiming.name, 'node');
@@ -58,8 +53,8 @@ function checkNodeTiming(timing) {
  // performance.now() i.e. measures Node.js instance up time.
  assert.strictEqual(typeof timing.duration, 'number');
  assert(timing.duration > 0, `timing.duration ${timing.duration} <= 0`);
- assert(delta < 10,
- `now (${now}) - timing.duration (${timing.duration}) = ${delta} >= ${10}`);
+ assert(delta < epsilon,
+ `now (${now}) - timing.duration (${timing.duration}) = ${delta} >= ${epsilon}`);
 
  // Check that the following fields do not change.
  assert.strictEqual(timing.startTime, initialTiming.startTime);
@@ -93,6 +88,18 @@ checkNodeTiming(initialTiming);
  assert(nodeStart < testStartTime,
  `nodeStart ${nodeStart} >= ${testStartTime}`);
 
+ {
+ // Due to https://github.com/nodejs/node/pull/46588,
+ // The difference between process.uptime() and (Date.now() - performance.timeOrigin)
+ // is roughly performance.nodeTiming.nodeStart
+ const uptime1 = Date.now() - performance.timeOrigin; // now - process start time
+ const uptime3 = process.uptime() * 1000; // now - node start time
+ assert(Math.abs(uptime1 - uptime3 - nodeStart) < epsilon,
+ `Date.now() - performance.timeOrigin (${uptime1}) - ` +
+ `process.uptime() * 1000 (${uptime3}) = ` +
+ `${uptime1 - uptime3} >= +- ${epsilon}`);
+ }
+
  assert.strictEqual(typeof v8Start, 'number');
  assert(v8Start > 0, `v8Start ${v8Start} <= 0`);
  // V8 starts after the process starts.