How paywalled sites permit access to visitors from social media sites and apps(elaineou.com)

    if (details.url.includes(url)) {

  if (details.url.includes(url)) {
    return true;
  }
  return false;

  return details.url.includes(url);

  array.map(someFunction).reduce(function(a, b) { return a ||b}, false)

  array.some(someFunction)

  var useTwitter = VIA_TWITTER.map(function(url) {
    if (details.url.includes(url)) {
      return true;
    }
    return false;
  })
  .reduce(function(a, b) { return a || b}, false);

  var useTwitter = VIA_TWITTER.some(function(url) {
    return details.url.includes(url);
  }

  var useTwitter = VIA_TWITTER.some(details.url.includes.bind(details.url));

  var useTwitter = VIA_TWITTER.some(url => details.url.includes(url));

  details.requestHeaders.filter(function(header) {

    // block cookies by default
    if (header.name !== "Cookie") {
      return header;
    } 

  })

  details.requestHeaders.filter(function(header) {
    // block cookies by default
    return header.name !== "Cookie";
  })

  var reqHeaders = …;
  reqHeaders.forEach(function(header) {
    if (header.name === "Referer") {
      header.value = setRefer(useTwitter);
      foundReferer = true;
    }
    if (header.name === "User-Agent") {
      header.value = setUserAgent(useTwitter);
      foundUA = true;
    }
  });

  function blockCookies(details) {
    for (var i = 0; i < details.responseHeaders.length; ++i) {
      if (details.responseHeaders[i].name === "Set-Cookie") {
        details.responseHeaders.splice(i, 1);
      }
    }
    return {responseHeaders: details.responseHeaders};
  }

  function blockCookies(details) {
    var headers = details.responseHeaders;
    var i = headers.length - 1;
    while (i > -1) {
      if (headers[i].name === "Set-Cookie") {
        headers.splice(i, 1);
      } else {
        i--;
      }
    }
    return {responseHeaders: headers};
  }