assert,util: improve unequal number comparison performance

BridgeAR · aduh95 · commit 696b5f85ca8a · 2025-05-19T12:13:48.000+02:00
This improves the performance to compare unequal numbers while doing a deep equal comparison. Comparing for NaN is faster by checking `variable !== variable` than by using `Number.isNaN()`. PR-URL: #57619 Reviewed-By: Jordan Harband <ljharb@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Chemi Atlow <chemi@atlow.co.il> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Edy Silva <edigleyssonsilva@gmail.com> Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com> Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
diff --git a/lib/internal/util/comparisons.js b/lib/internal/util/comparisons.js
@@ -8,7 +8,6 @@ const {
   BooleanPrototypeValueOf,
   DatePrototypeGetTime,
   Error,
-  NumberIsNaN,
   NumberPrototypeValueOf,
   ObjectGetOwnPropertySymbols: getOwnSymbols,
   ObjectGetPrototypeOf,
@@ -183,7 +182,9 @@ function innerDeepEqual(val1, val2, mode, memos) {
   // Check more closely if val1 and val2 are equal.
   if (mode !== kLoose) {
     if (typeof val1 === 'number') {
-      return NumberIsNaN(val1) && NumberIsNaN(val2);
+      // Check for NaN
+      // eslint-disable-next-line no-self-compare
+      return val1 !== val1 && val2 !== val2;
     }
     if (typeof val2 !== 'object' ||
         typeof val1 !== 'object' ||
@@ -195,8 +196,9 @@ function innerDeepEqual(val1, val2, mode, memos) {
   } else {
     if (val1 === null || typeof val1 !== 'object') {
       return (val2 === null || typeof val2 !== 'object') &&
-             // eslint-disable-next-line eqeqeq
-             (val1 == val2 || (NumberIsNaN(val1) && NumberIsNaN(val2)));
+             // Check for NaN
+             // eslint-disable-next-line eqeqeq, no-self-compare
+             (val1 == val2 || (val1 !== val1 && val2 !== val2));
     }
     if (val2 === null || typeof val2 !== 'object') {
       return false;
@@ -494,7 +496,9 @@ function findLooseMatchingPrimitives(prim) {
       // a regular number and not NaN.
       // Fall through
     case 'number':
-      if (NumberIsNaN(prim)) {
+      // Check for NaN
+      // eslint-disable-next-line no-self-compare
+      if (prim !== prim) {
         return false;
       }
   }
