From b9dcc690961f34b22517d367ad9a7c68babfe43a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20B=C3=B6sch-Plepelits?= <skunk@xover.mud.at>
Date: Wed, 19 Nov 2025 21:03:03 +0100
Subject: [PATCH] Add a 'numberPrecision' option

If comparing numbers, rounding errors may be allowed up to a specified precision.
Usage:
deepEqualCheck([ 1, 2 ], [ 1, 2.000000001 ], { numberPrecision: 0.000001 }) -> true
---
 src/index.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/index.ts b/src/index.ts
index 1f2cbd7..d927707 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -19,6 +19,10 @@ function deepEqualCore(
     return options.nanEqual;
   }
 
+  if (typeof a === 'number' && typeof b === 'number' && options.numberPrecision && Math.abs(a - b) < options.numberPrecision) {
+    return true;
+  }
+
   // Fast path: if both are primitives (not objects/functions), return false
   if (
     (a === null || typeof a !== 'object' && typeof a !== 'function') &&
@@ -303,6 +307,7 @@ export function deepEqualCheck<T = unknown>(
     checkPrototypes: options.checkPrototypes ?? false,
     strictZero: options.strictZero ?? false,
     maxDepth: options.maxDepth ?? 1000,
+    numberPrecision: options.numberPrecision ?? false,
   };
   
   return deepEqualCore(a, b, opts, new WeakMap(), 0);