From 900c80295e0dccd4035beaaf68e25aba1d372069 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Bargull?= <andre.bargull@gmail.com>
Date: Wed, 18 Dec 2024 11:05:56 +0100
Subject: [PATCH] Don't call assert.deepEqual.format when the assertion will
 succeed

---
 harness/deepEqual.js | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/harness/deepEqual.js b/harness/deepEqual.js
index 0cd0a49dac..b695c89580 100644
--- a/harness/deepEqual.js
+++ b/harness/deepEqual.js
@@ -8,10 +8,15 @@ defines: [assert.deepEqual]
 
 assert.deepEqual = function(actual, expected, message) {
   var format = assert.deepEqual.format;
-  assert(
-    assert.deepEqual._compare(actual, expected),
-    `Expected ${format(actual)} to be structurally equal to ${format(expected)}. ${(message || '')}`
-  );
+  var mustBeTrue = assert.deepEqual._compare(actual, expected);
+
+  // format can be slow when `actual` or `expected` are large objects, like for
+  // example the global object, so only call it when the assertion will fail.
+  if (mustBeTrue !== true) {
+    message = `Expected ${format(actual)} to be structurally equal to ${format(expected)}. ${(message || '')}`;
+  }
+
+  assert(mustBeTrue, message);
 };
 
 (function() {