feat(perf): Hoist RegExp literals in RequestShortener

TheLarkInn · TheLarkInn · commit 998c2bb21030 · 2017-06-30T14:46:59.000-05:00
diff --git a/lib/RequestShortener.js b/lib/RequestShortener.js
@@ -5,30 +5,43 @@
 "use strict";
 
 const path = require("path");
+const NORMALIZE_SLASH_DIRECTION_REGEXP = /\\/g;
+const PATH_CHARS_REGEXP = /[-[\]{}()*+?.,\\^$|#\s]/g;
+const SEPERATOR_REGEXP = /[\/\\]$/;
+
+
+const normalizeBackSlashDirection = (request) => {
+	return request.replace(NORMALIZE_SLASH_DIRECTION_REGEXP, "/");
+};
+
+const shortenPath = (path) => {
+	return path.replace(PATH_CHARS_REGEXP, "\\$&");
+};
+
 
 class RequestShortener {
 	constructor(directory) {
-		directory = directory.replace(/\\/g, "/");
+		directory = normalizeBackSlashDirection(directory);
 		if(/[\/\\]$/.test(directory)) directory = directory.substr(0, directory.length - 1);
 
 		if(directory) {
-			const currentDirectoryRegExpString = directory.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
+			const currentDirectoryRegExpString = shortenPath(directory);
 			this.currentDirectoryRegExp = new RegExp("^" + currentDirectoryRegExpString + "|(!)" + currentDirectoryRegExpString, "g");
 		}
 
 		const dirname = path.dirname(directory);
-		const endsWithSeperator = /[\/\\]$/.test(dirname);
+		const endsWithSeperator = SEPERATOR_REGEXP.test(dirname);
 		const parentDirectory = endsWithSeperator ? dirname.substr(0, dirname.length - 1) : dirname;
 		if(parentDirectory && parentDirectory !== directory) {
-			const parentDirectoryRegExpString = parentDirectory.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
+			const parentDirectoryRegExpString = shortenPath(parentDirectory);
 			this.parentDirectoryRegExp = new RegExp("^" + parentDirectoryRegExpString + "|(!)" + parentDirectoryRegExpString, "g");
 		}
 
 		if(__dirname.length >= 2) {
-			const buildins = path.join(__dirname, "..").replace(/\\/g, "/");
+			const buildins = normalizeBackSlashDirection(path.join(__dirname, ".."));
 			const buildinsAsModule = this.currentDirectoryRegExp && this.currentDirectoryRegExp.test(buildins);
 			this.buildinsAsModule = buildinsAsModule;
-			const buildinsRegExpString = buildins.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, "\\$&");
+			const buildinsRegExpString = shortenPath(buildins);
 			this.buildinsRegExp = new RegExp("^" + buildinsRegExpString + "|(!)" + buildinsRegExpString, "g");
 		}
 
@@ -37,7 +50,7 @@ class RequestShortener {
 
 	shorten(request) {
 		if(!request) return request;
-		request = request.replace(/\\/g, "/");
+		request = normalizeBackSlashDirection(request);
 		if(this.buildinsAsModule && this.buildinsRegExp)
 			request = request.replace(this.buildinsRegExp, "!(webpack)");
 		if(this.currentDirectoryRegExp)
