From 3f25c324147d95293d7ff1481e4b8c0ee1f83abb Mon Sep 17 00:00:00 2001
From: Nick Gavalas <nick.j.gavalas@gmail.com>
Date: Tue, 7 Mar 2023 22:32:13 -0600
Subject: [PATCH] perf: swap order of escape regexes to avoid lookahead (#546)

* swap regex order to avoid lookahead

* changelog

* changelog formatting apparently
---
 CHANGELOG.md    | 3 +++
 lib/registry.js | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6f6f85b4..f1218536 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,9 @@ project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
+- Refactor `escapeString` helper in `lib/registry.js` to improve performance and
+  avoid an unnecessarily complex regex.
+
 ### Added
 
 - Support for OpenMetrics and Exemplars
diff --git a/lib/registry.js b/lib/registry.js
index 127c659a..70d4f5ce 100644
--- a/lib/registry.js
+++ b/lib/registry.js
@@ -214,7 +214,7 @@ function escapeLabelValue(str) {
 	return escapeString(str).replace(/"/g, '\\"');
 }
 function escapeString(str) {
-	return str.replace(/\n/g, '\\n').replace(/\\(?!n)/g, '\\\\');
+	return str.replace(/\\/g, '\\\\').replace(/\n/g, '\\n');
 }
 function standardizeCounterName(name) {
 	return name.replace(/_total$/, '');