Fix: Hack for iOS 15 history back scroll bug

iOS-15-History-Back-Scroll-Bug-Fix.js

(() => {
  if (!navigator.userAgent.includes('iPhone OS')) {
    return;
  }
  
  const STORE_KEY = '_ios_scroll_bug';
  
  window.addEventListener('pagehide', () => {
    sessionStorage.setItem(STORE_KEY, window.scrollY);
  });
  
  window.addEventListener('pageshow', (event) => {
    if (!event.persisted) {
      return;
    }
  
    const store = sessionStorage.getItem(STORE_KEY);
    if (!store) {
      return;
    }
  
    const storedScrollY = parseInt(store, 10);
  
    if (storedScrollY && storedScrollY > window.scrollY) {
      setTimeout(() => window.scrollTo(0, storedScrollY), 100);
    }
  });
})();

Maybe something like this would prevent the page looking jumpy?

(() => {
  if (!navigator.userAgent.includes('iPhone OS')) {
    return;
  }
  
  const STORE_KEY = '_ios_scroll_bug';
  
  window.addEventListener('pagehide', () => {
    sessionStorage.setItem(STORE_KEY, window.scrollY);
  });
  
  window.addEventListener('pageshow', (event) => {
    if (!event.persisted) {
      return;
    }
    document.body.style.visibility = "hidden";
    const store = sessionStorage.getItem(STORE_KEY);
    if (!store) {
      return;
    }
  
    const storedScrollY = parseInt(store, 10);
  
    if (storedScrollY && storedScrollY > window.scrollY) {
      setTimeout(() => {
        window.scrollTo(0, storedScrollY);
        document.body.style.visibility = "visible";
      }, 100);
    }

  });
})();

@eeue56 if the store (sessionStorage.getItem) fail you return without setting the body to visible again