Extract escapeRegExp().

src/util/escape-regexp.js

@@ -0,0 +1,17 @@
+import shared from "../shared.js"
+
+function init() {
+  const specialCharRegExp = /[\\^$.*+?()[\]{}|]/g
+
+  function escapeRegExp(string) {
+    return typeof string === "string"
+      ? string.replace(specialCharRegExp, "\\$&")
+      : ""
+  }
+
+  return escapeRegExp
+}
+
+export default shared.inited
+  ? shared.module.utilEscapeRegExp
+  : shared.module.utilEscapeRegExp = init()

src/util/is-native.js

@@ -1,3 +1,4 @@
+import escapeRegExp from "./escape-regexp.js"
 import isProxy from "./is-proxy.js"
 import shared from "../shared.js"
 
@@ -10,11 +11,10 @@ function init() {
   // compare other native methods against. Escape special RegExp characters
   // and remove method identifiers before converting the template to a regexp.
   const markerRegExp = /toString|(function ).*?(?=\\\()/g
-  const specialCharRegExp = /[\\^$.*+?()[\]{}|]/g
+
   const nativeRegExp = RegExp(
     "^" +
-    toString.call(toString)
-      .replace(specialCharRegExp, "\\$&")
+    escapeRegExp(toString.call(toString))
       .replace(markerRegExp, "$1.*?") +
     "$"
   )