httpsRedirect

Redirects the page to HTTPS if it's currently in HTTP.

• Use location.protocol to get the protocol currently being used.
• If it's not HTTPS, use location.replace() to replace the existing page with the HTTPS version of the page.
• Use location.href to get the full address, split it with String.prototype.split() and remove the protocol part of the URL.
• Note that pressing the back button doesn't take it back to the HTTP page as its replaced in the history.

const httpsRedirect = () => {
  if (location.protocol !== 'https:')
    location.replace('https://' + location.href.split('//')[1]);
};

httpsRedirect(); 
// If you are on http://mydomain.com, you are redirected to https://mydomain.com