CheckAdoptions.js

var CheckAdoptions = function () {
        this._adoptions = [];
        this._concerns  = [];
        return this;
};

CheckAdoptions.prototype.__fetchAdoptionsList = function () {
        if (this._adoptions.length > 0) {
                this._adoptions = [];
                this._concerns  = [];
        }

        return new Promise(function (resolve, reject) {
                var _payload = {
                        action:      'query',
                        list:        'recentchanges',
                        rcprop:      'title|sizes',
                        rcnamespace: '118',
                        format:      'json'
                };

                $.ajax({
                        url:      mw.util.wikiScript('api'),
                        type:     'POST',
                        dataType: 'JSON',
                        data:     _payload
                })
                        .success(function(data) {
                                resolve(data.query.recentchanges);
                        })
                        .error(function(err, status) {
                                reject(err, status);
                        });
        });
};

CheckAdoptions.prototype.__markConcerns = function () {
        if (this._concerns.length === 0) return;

        var __changeLinks = document.querySelectorAll('.mw-conntent a');

        for (var i = 0; i < __changeLinks.length; i++) {
                if (this._concerns.includes(__changeLinks[i].title))
                        __changeLinks[i].parentNode.parentNode.style.backgroundColor = '#FF0000';
        }

        this._adoptions = [];
        this._concerns  = [];
};

CheckAdoptions.prototype.init = function () {
        if (mw.config.get('wgCanonicalSpecialPageName') !== 'Recentchanges')
                return;

        this.__fetchAdoptionsList()
                .then(
                        function (data) {
                                for (var i = 0; i < data.length; i++) {
                                        if (data[i].oldlen > data[i].newlen)
                                                this._concerns.push(data[i].title);
                                }

                                this.__markConcerns();
                        }.bind(this),
                        function (error, status) {
                                console.error('Error: [' + status + '] ' + error);
                        }
                );
};