From f51e0742d7b1597e212150c6bd5a1042ab3e9b88 Mon Sep 17 00:00:00 2001
From: Xmader <xmader@outlook.com>
Date: Thu, 5 Nov 2020 16:36:24 -0500
Subject: [PATCH] fix: anti-detection

---
 src/anti-detection.ts | 26 ++++++++++++++++++++++++++
 src/file.ts           | 11 ++---------
 2 files changed, 28 insertions(+), 9 deletions(-)
 create mode 100644 src/anti-detection.ts

diff --git a/src/anti-detection.ts b/src/anti-detection.ts
new file mode 100644
index 0000000..65ed729
--- /dev/null
+++ b/src/anti-detection.ts
@@ -0,0 +1,26 @@
+/* eslint-disable no-extend-native */
+/* eslint-disable @typescript-eslint/ban-types */
+
+/**
+ * make hooked methods "native"
+ */
+export const makeNative = (() => {
+  const l: Set<Function> = new Set()
+
+  const _toString = Function.prototype['toString']
+  const toString = function () {
+    if (l.has(this)) {
+      // "function () {\n    [native code]\n}"
+      return _toString.call(parseInt) as string
+    }
+    return _toString.call(this) as string
+  }
+  Function.prototype.toString = toString
+
+  // make `Function.prototype.toString` itself "native"
+  l.add(toString)
+
+  return (fn: Function) => {
+    l.add(fn)
+  }
+})()
diff --git a/src/file.ts b/src/file.ts
index 2cc6f54..0d41ca1 100644
--- a/src/file.ts
+++ b/src/file.ts
@@ -2,6 +2,7 @@
 
 import scoreinfo from './scoreinfo'
 import { webpackHook } from './webpack-hook'
+import { makeNative } from './anti-detection'
 
 const FILE_URL_MODULE_ID = 'iNJA'
 const MAGIC_REG = /^\d+(img|mp3|midi)\d(.+)$/
@@ -35,15 +36,7 @@ let magic: Promise<string> | string = new Promise((resolve) => {
   }
   target[method] = hookFn
 
-  // make hooked methods "native"
-  const _toString = Function.prototype['toString']
-  Function.prototype.toString = function s () {
-    if (this === hookFn || this === s) {
-      // "function () {\n    [native code]\n}"
-      return _toString.call(parseInt) as string
-    }
-    return _toString.call(this) as string
-  }
+  makeNative(hookFn)
 })
 
 export const getFileUrl = async (type: FileType, index = 0): Promise<string> => {