Google Apps Script での 「oAuthConfig」のサポート終了後用の Twitter API スクリプト。「OAuth1」ライブラリ(ID：Mb2Vpd5nfD3Pz-_a-39Q4VfxhMjh3Sh48）が必要。

twitter.gs

// 最初にこの関数を実行し、ログに出力されたURLにアクセスしてOAuth認証する
function twitterAuthorizeUrl() {
  Twitter.oauth.showUrl();
}

// OAuth認証成功後のコールバック関数
function twitterAuthorizeCallback(request) {
  return Twitter.oauth.callback(request);
}

// OAuth認証のキャッシュをを削除する場合はこれを実行（実行後は再度認証が必要）
function twitterAuthorizeClear() {
  Twitter.oauth.clear();
}


var Twitter = {
  projectKey: "MXappA_xT0MjWFoTcgW6A42Y-OyNWyuNg",
  
  consumerKey: "OgPlFpMkihcAIgVkOWi1g",
  consumerSecret: "Tn0gvGGizaI6GZbrli8mTr2Hggz8vb2bU7vbXlT7ws",
  
  apiUrl: "https://api.twitter.com/1.1/",
  
  oauth: {
    name: "twitter",
    
    service: function(screen_name) {
      // 参照元：https://github.com/googlesamples/apps-script-oauth2
      
      return OAuth1.createService(this.name)
      // Set the endpoint URLs.
      .setAccessTokenUrl('https://api.twitter.com/oauth/access_token')
      .setRequestTokenUrl('https://api.twitter.com/oauth/request_token')
      .setAuthorizationUrl('https://api.twitter.com/oauth/authorize')
      
      // Set the consumer key and secret.
      .setConsumerKey(this.parent.consumerKey)
      .setConsumerSecret(this.parent.consumerSecret)
      
      // Set the project key of the script using this library.
      .setProjectKey(this.parent.projectKey)
      
      
      // Set the name of the callback function in the script referenced
      // above that should be invoked to complete the OAuth flow.
      .setCallbackFunction('twitterAuthorizeCallback')
      
      // Set the property store where authorized tokens should be persisted.
      .setPropertyStore(PropertiesService.getUserProperties());
    },
    
    showUrl: function() {
      var service = this.service();
      if (!service.hasAccess()) {
        Logger.log(service.authorize());
      } else {
        Logger.log("認証済みです");
      }
    },
    
    callback: function (request) {
      var service = this.service();
      var isAuthorized = service.handleCallback(request);
      if (isAuthorized) {
        return HtmlService.createHtmlOutput("認証に成功しました！このタブは閉じてかまいません。");
      } else {
        return HtmlService.createHtmlOutput("認証に失敗しました・・・");
      }
    },
    
    clear: function(){
      OAuth1.createService(this.name)
      .setPropertyStore(PropertiesService.getUserProperties())
      .reset();
    }
  },
  
  api: function(path, data) {
    var that = this, service = this.oauth.service();
    if (!service.hasAccess()) {
      Logger.log("先にOAuth認証してください");
      return false;
    }
    
    path = path.toLowerCase().replace(/^\//, '').replace(/\.json$/, '');
    
    var method = (
         /^statuses\/(destroy\/\d+|update|retweet\/\d+)/.test(path)
      || /^media\/upload/.test(path)
      || /^direct_messages\/(destroy|new)/.test(path)
      || /^friendships\/(create|destroy|update)/.test(path)
      || /^account\/(settings|update|remove)/.test(path)
      || /^blocks\/(create|destroy)/.test(path)
      || /^mutes\/users\/(create|destroy)/.test(path)
      || /^favorites\/(destroy|create)/.test(path)
      || /^lists\/[^\/]+\/(destroy|create|update)/.test(path)
      || /^saved_searches\/(create|destroy)/.test(path)
      || /^geo\/place/.test(path)
      || /^users\/report_spam/.test(path)
      ) ? "post" : "get";
    
    var url = this.apiUrl + path + ".json";
    var options = {
      method: method,
      muteHttpExceptions: true
    };
    
    if ("get" === method) {
      if (!this.isEmpty(data)) {
        // 2015/07/07 再度修正
        // 旧コード）
        // var queries = [];
        // for (var key in data) {
        //   // 2015/05/28 以下の部分を修正
        //   // 旧コード） queries.push(key + "=" + encodeURIComponent(data[key]));
        //   
        //   
        //   var encoded = encodeURIComponent(data[key]).replace(/[!'()*]/g, function(c) {
        //     return "%" + c.charCodeAt(0).toString(16);
        //   });
        //   queries.push(key + "=" + encoded);
        // }
        // url += '?' + queries.join("&");
        url += '?' + Object.keys(data).map(function(key) {
          return that.encodeRfc3986(key) + '=' + that.encodeRfc3986(data[key]);
        }).join('&');
      }
    } else if ("post" == method) {
      if (!this.isEmpty(data)) {
        // 2015/07/07 修正
        // 旧コード）options.payload = data;
        options.payload = Object.keys(data).map(function(key) {
          return that.encodeRfc3986(key) + '=' + that.encodeRfc3986(data[key]);
        }).join('&');
        
        if (data.media) {
          options.contentType = "multipart/form-data;charset=UTF-8";
        }
      }
    }

    try {
      var result = service.fetch(url, options);
      var json = JSON.parse(result.getContentText());
      if (json) {
        if (json.error) {
          throw new Error(json.error + " (" + json.request + ")");
        } else if (json.errors) {
          var err = [];
          for (var i = 0, l = json.errors.length; i < l; i++) {
            var error = json.errors[i];
            err.push(error.message + " (code: " + error.code + ")");
          }
          throw new Error(err.join("\n"));
        } else {
          return json;
        }
      }
    } catch(e) {
      this.error(e);
    }
    
    return false;
  },
  
  error: function(error) {
    var message = null;
    if ('object' === typeof error && error.message) {
      message = error.message + " ('" + error.fileName + '.gs:' + error.lineNumber +")";
    } else {
      message = error;
    }
    
    Logger.log(message);
  },
  
  isEmpty: function(obj) {
    if (obj == null) return true;
    if (obj.length > 0)    return false;
    if (obj.length === 0)  return true;
    for (var key in obj) {
        if (hasOwnProperty.call(obj, key)) return false;
    }
    return true;
  },
  
  encodeRfc3986: function(str) {
    return encodeURIComponent(str).replace(/[!'()]/g, function(char) {
      return escape(char);
    }).replace(/\*/g, "%2A");
  },
  
  init: function() {
    this.oauth.parent = this;
    return this;
  }
}.init();


/********************************************************************
以下はサポート関数
*/

// ツイート検索
Twitter.search = function(data) {
  if ("string" === typeof data) {
    data = {q: data};
  }
  
  return this.api("search/tweets", data);
};

// 自分のタイムライン取得
Twitter.tl = function(since_id) {
  var data = null;
  
  if ("number" === typeof since_id || /^\d+$/.test(''+since_id)) {
    data = {since_id: since_id};
  } else if("object" === typeof since_id) {
    data = since_id;
  }
  
  return this.api("statuses/home_timeline", data);
};

// ユーザーのタイムライン取得
Twitter.usertl = function(user, since_id) {
  var path = "statuses/user_timeline";
  var data = {};
  
  if (user) {
    if (/^\d+$/.test(user)) {
      data.user_id = user;
    } else {
      data.screen_name = user;
    }
  } else {
    var path = "statuses/home_timeline";
  }
  
  if (since_id) {
    data.since_id = since_id;
  }
  
  return this.api(path, data);
};

// ツイートする
Twitter.tweet = function(data, reply) {
  var path = "statuses/update";
  if ("string" === typeof data) {
    data = {status: data};
  } else if(data.media) {
    path = "statuses/update_with_media ";
  }
  
  if (reply) {
    data.in_reply_to_status_id = reply;
  }
  
  return this.api(path, data);
};

// トレンド取得（日本）
Twitter.trends = function(woeid) {
  data = {id: woeid || 1118108};
  var res = this.api("trends/place", data);
  return (res && res[0] && res[0].trends && res[0].trends.length) ? res[0].trends : null;
};

// トレンドのワードのみ取得
Twitter.trendWords = function(woeid) {
  data = {id: woeid || 1118108};
  var res = this.api("trends/place", data);
  if (res && res[0] && res[0].trends && res[0].trends.length) {
    var trends = res[0].trends;
    var words = [];
    for(var i = 0, l = trends.length; i < l; i++) {
      words.push(trends[i].name);
    }
    return words;
  }
};