From b5d81abfd26ca3402abe114cd229f0ad00fb10f5 Mon Sep 17 00:00:00 2001
From: Xmader <xmader@outlook.com>
Date: Thu, 5 Nov 2020 17:18:43 -0500
Subject: [PATCH] feat: btn anti-detection

---
 src/anti-detection.ts | 18 +++++++++++++++++-
 src/btn.ts            | 10 +++++++++-
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/anti-detection.ts b/src/anti-detection.ts
index aa8d18d..0d85a9b 100644
--- a/src/anti-detection.ts
+++ b/src/anti-detection.ts
@@ -5,7 +5,7 @@
  * make hooked methods "native"
  */
 export const makeNative = (() => {
-  const l: Set<Function> = new Set()
+  const l = new Set<Function>()
 
   hookNative(Function.prototype, 'toString', (_toString) => {
     return function () {
@@ -42,3 +42,19 @@ export function hookNative<T extends object, M extends (keyof T)> (
     makeNative(hookedFn as any)
   })
 }
+
+export const hideFromArrFilter = (() => {
+  const l = new Set()
+
+  hookNative(Array.prototype, 'filter', (_filter) => {
+    return function (...args) {
+      const arr = _filter.apply(this, args)
+      // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+      return _filter.call(arr, (e) => !l.has(e))
+    }
+  })
+
+  return (item: any) => {
+    l.add(item)
+  }
+})()
diff --git a/src/btn.ts b/src/btn.ts
index 9ebbc50..9e19571 100644
--- a/src/btn.ts
+++ b/src/btn.ts
@@ -1,5 +1,6 @@
 
 import { loadMscore, WebMscore } from './mscore'
+import { hideFromArrFilter } from './anti-detection'
 import i18n from './i18n'
 
 type BtnElement = HTMLButtonElement
@@ -42,6 +43,10 @@ export class BtnList {
 
   private antiDetectionText = 'Download'
 
+  private hide (el: HTMLElement) {
+    hideFromArrFilter(el)
+  }
+
   add (options: BtnOptions): BtnElement {
     const btn = this.templateBtn.cloneNode(true) as HTMLButtonElement
 
@@ -60,10 +65,13 @@ export class BtnList {
       get: () => {
         // first time only
         const t = this.antiDetectionText
-        this.antiDetectionText = ''
+        this.antiDetectionText = ' '
         return t
       },
     })
+    // hide this button from Array.prototype.filter
+    this.hide(btn)
+    this.hide(textNode)
 
     const setText = (str: string): void => {
       textNode.textContent = str