From 536032852cc8fe0dd1ac479cea70fc9682149cb5 Mon Sep 17 00:00:00 2001
From: Nam Hoang Le <nam.hoang.le@mgm-tp.com>
Date: Sun, 14 Nov 2021 13:52:13 +0700
Subject: [PATCH 1/2] Move regexp to outer scope

---
 index.js | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/index.js b/index.js
index cdb5511..785080f 100644
--- a/index.js
+++ b/index.js
@@ -1,5 +1,15 @@
 'use strict';
 
+const UPPER_CASE = /[\p{Lu}]/u;
+const LOWER_CASE = /[\p{Ll}]/u;
+const LEADING_CAPITAL = /^[\p{Lu}](?![\p{Lu}])/gu;
+const IDENTIFIER = /([\p{Alpha}\p{N}_]|$)/u;
+const SEPARATORS = /[_.\- ]+/;
+
+const LEADING_SEPARATORS = new RegExp('^' + SEPARATORS.source);
+const SEPARATORS_AND_IDENTIFIER = new RegExp(SEPARATORS.source + IDENTIFIER.source, 'gu');
+const NUMBERS_AND_IDENTIFIER = new RegExp('\\d+' + IDENTIFIER.source, 'gu');
+
 const preserveCamelCase = (string, locale) => {
 	let isLastCharLower = false;
 	let isLastCharUpper = false;
@@ -8,13 +18,13 @@ const preserveCamelCase = (string, locale) => {
 	for (let i = 0; i < string.length; i++) {
 		const character = string[i];
 
-		if (isLastCharLower && /[\p{Lu}]/u.test(character)) {
+		if (isLastCharLower && UPPER_CASE.test(character)) {
 			string = string.slice(0, i) + '-' + string.slice(i);
 			isLastCharLower = false;
 			isLastLastCharUpper = isLastCharUpper;
 			isLastCharUpper = true;
 			i++;
-		} else if (isLastCharUpper && isLastLastCharUpper && /[\p{Ll}]/u.test(character)) {
+		} else if (isLastCharUpper && isLastLastCharUpper && LOWER_CASE.test(character)) {
 			string = string.slice(0, i - 1) + '-' + string.slice(i - 1);
 			isLastLastCharUpper = isLastCharUpper;
 			isLastCharUpper = false;
@@ -30,12 +40,12 @@ const preserveCamelCase = (string, locale) => {
 };
 
 const preserveConsecutiveUppercase = input => {
-	return input.replace(/^[\p{Lu}](?![\p{Lu}])/gu, m1 => m1.toLowerCase());
+	return input.replace(LEADING_CAPITAL, m1 => m1.toLowerCase());
 };
 
 const postProcess = (input, options) => {
-	return input.replace(/[_.\- ]+([\p{Alpha}\p{N}_]|$)/gu, (_, p1) => p1.toLocaleUpperCase(options.locale))
-		.replace(/\d+([\p{Alpha}\p{N}_]|$)/gu, m => m.toLocaleUpperCase(options.locale));
+	return input.replace(SEPARATORS_AND_IDENTIFIER, (_, identifier) => identifier.toLocaleUpperCase(options.locale))
+		.replace(NUMBERS_AND_IDENTIFIER, m => m.toLocaleUpperCase(options.locale));
 };
 
 const camelCase = (input, options) => {
@@ -71,7 +81,7 @@ const camelCase = (input, options) => {
 		input = preserveCamelCase(input, options.locale);
 	}
 
-	input = input.replace(/^[_.\- ]+/, '');
+	input = input.replace(LEADING_SEPARATORS, '');
 
 	if (options.preserveConsecutiveUppercase) {
 		input = preserveConsecutiveUppercase(input);

From c1baa3a94a77d37ecc8b8f49a4dbf9c993df31a5 Mon Sep 17 00:00:00 2001
From: Nam Hoang Le <nam.hoang.le@mgm-tp.com>
Date: Mon, 15 Nov 2021 09:37:43 +0700
Subject: [PATCH 2/2] Rename and reset lastIndex for global regexp

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

diff --git a/index.js b/index.js
index 785080f..b501478 100644
--- a/index.js
+++ b/index.js
@@ -1,7 +1,7 @@
 'use strict';
 
-const UPPER_CASE = /[\p{Lu}]/u;
-const LOWER_CASE = /[\p{Ll}]/u;
+const UPPERCASE = /[\p{Lu}]/u;
+const LOWERCASE = /[\p{Ll}]/u;
 const LEADING_CAPITAL = /^[\p{Lu}](?![\p{Lu}])/gu;
 const IDENTIFIER = /([\p{Alpha}\p{N}_]|$)/u;
 const SEPARATORS = /[_.\- ]+/;
@@ -18,13 +18,13 @@ const preserveCamelCase = (string, locale) => {
 	for (let i = 0; i < string.length; i++) {
 		const character = string[i];
 
-		if (isLastCharLower && UPPER_CASE.test(character)) {
+		if (isLastCharLower && UPPERCASE.test(character)) {
 			string = string.slice(0, i) + '-' + string.slice(i);
 			isLastCharLower = false;
 			isLastLastCharUpper = isLastCharUpper;
 			isLastCharUpper = true;
 			i++;
-		} else if (isLastCharUpper && isLastLastCharUpper && LOWER_CASE.test(character)) {
+		} else if (isLastCharUpper && isLastLastCharUpper && LOWERCASE.test(character)) {
 			string = string.slice(0, i - 1) + '-' + string.slice(i - 1);
 			isLastLastCharUpper = isLastCharUpper;
 			isLastCharUpper = false;
@@ -40,10 +40,15 @@ const preserveCamelCase = (string, locale) => {
 };
 
 const preserveConsecutiveUppercase = input => {
+	LEADING_CAPITAL.lastIndex = 0;
+
 	return input.replace(LEADING_CAPITAL, m1 => m1.toLowerCase());
 };
 
 const postProcess = (input, options) => {
+	SEPARATORS_AND_IDENTIFIER.lastIndex = 0;
+	NUMBERS_AND_IDENTIFIER.lastIndex = 0;
+
 	return input.replace(SEPARATORS_AND_IDENTIFIER, (_, identifier) => identifier.toLocaleUpperCase(options.locale))
 		.replace(NUMBERS_AND_IDENTIFIER, m => m.toLocaleUpperCase(options.locale));
 };