mute-from-list.js

// ==UserScript==
// @name         BTD from_list mute filter
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  mm
// @author       You
// @match        https://tweetdeck.twitter.com
// @grant        none
// ==/UserScript==

setTimeout(function() {
    'use strict';
    const { BTD, TD } = window;
    const eventuals = new Map();
    console.debug('mute from list eventuals', eventuals); // useful to get a handle on the Map for debugging

    /*
    function makeTwitterCall(e: absolute url, t: params, i: method, n: ?processor, s: success callback, r: error callback, o: ?feedtype);
    TD.services.TwitterClient.prototype.getListMembers = function(e: {
        id: list id,
        cursor: <unsure, defaults to -1>,
        count: <unsure, defaults to 20>
    }, t: success callback, i: error callback);
    */

    function listMembers (name) {
        const list = TD.cache.lists.getAll().find(l => l.name === name);
        if (!list) return Promise.resolve([]);

        const twitter = TD.controller.clients.getPreferredClient("twitter");
        return new Promise((resolve, reject) => twitter.getListMembers({ id: list.id, count: 500 }, resolve, reject))
    }

    function eventuallyCheckForAppartenanceToAList (listname) {
        const eventually = {
            members: listMembers(listname).then(data => {
                eventually.members = data.users;
                eventually.ready = true;
            }).catch(console.log),
            ready: false
        };

        return function (user_id) {
            if (!eventually.ready) return false;
            return eventually.members.some(member => member.id === user_id);
        }
    }

    const oldfilters = BTD.filterDropdown();
    BTD.Filters.BTD_from_list = {
        display: {
            global: true,
        },
        name: 'Users from a List',
        descriptor: 'tweets posted or retweeted by any user on a list',
        placeholder: 'name of a list you own',
        function (filter, tweet) {
            const key = filter.value + '';
            if (!eventuals.has(key)) {
                eventuals.set(key, eventuallyCheckForAppartenanceToAList(key));
            }

            try {
                if (!tweet.user || !tweet.user.id) return true; // sometimes those are undefined
                return !eventuals.get(key)(tweet.user.id);
            } catch (e) {
                console.log(e);
            } finally {
                return true;
            }
        }
    };

    TD.mustaches['settings/global_setting_filter.mustache'] = TD.mustaches[
        'settings/global_setting_filter.mustache'
    ].replace(oldfilters, BTD.filterDropdown());
}, 1000);

It was an experimental BTD plugin for muting all members of a given list. But who are you and why are you asking about gists that are years past dead.