Refactor regexp quoting

Diogo Franco (Kovensky) · Diogo Franco (Kovensky) · commit e9697cbcd578 · 2016-11-21T08:37:22.000+09:00
diff --git a/lib/dependencies/ContextDependencyHelpers.js b/lib/dependencies/ContextDependencyHelpers.js
@@ -4,6 +4,15 @@
 */
 var ContextDependencyHelpers = exports;
 
+/**
+ * Escapes regular expression metacharacters
+ * @param {string} str
+ * @return string
+ */
+function quotemeta(str) {
+	return str.replace(/[-[\]\\/{}()*+?.^$|]/g, "\\$&")
+}
+
 ContextDependencyHelpers.create = function(Dep, range, param, expr, options) {
 	var dep, prefix, postfix, prefixRange, valueRange, idx, context, regExp;
 	if(param.isTemplateString()) {
@@ -19,9 +28,9 @@ ContextDependencyHelpers.create = function(Dep, range, param, expr, options) {
 		}
 		// If there are more than two quasis, maybe the generated RegExp can be more precise?
 		regExp = new RegExp("^" +
-			prefix.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&") +
+			quotemeta(prefix) +
 			options.wrappedContextRegExp.source +
-			postfix.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&") + "$");
+			quotemeta(postfix) + "$");
 		dep = new Dep(context, options.wrappedContextRecursive, regExp, range, valueRange);
 		dep.loc = expr.loc;
 		dep.replaces = [{
@@ -42,9 +51,9 @@ ContextDependencyHelpers.create = function(Dep, range, param, expr, options) {
 			prefix = "." + prefix.substr(idx);
 		}
 		regExp = new RegExp("^" +
-			prefix.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&") +
+			quotemeta(prefix) +
 			options.wrappedContextRegExp.source +
-			postfix.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&") + "$");
+			quotemeta(postfix) + "$");
 		dep = new Dep(context, options.wrappedContextRecursive, regExp, range, valueRange);
 		dep.loc = expr.loc;
 		dep.prepend = param.prefix && param.prefix.isString() ? prefix : null;
