Javascript UserAgent Manipulator

UserAgents.js

class UserAgents
{
    constructor(targetWindow) {
        this.window = targetWindow || window;
    }
    /**
     * Creates a read/writable property which returns a function set for write/set (assignment)
     * and read/get access on a variable
     *
     * @param {Any} value initial value of the property
     */
    createProperty (value) {
        var _value = value;

        /**
         * Overwrite getter.
         *
         * @returns {Any} The Value.
         * @private
         */
        function _get () {
            return _value;
        }

        /**
         * Overwrite setter.
         *
         * @param {Any} v   Sets the value.
         * @private
         */
        function _set (v) {
            _value = v;
        }

        return {
            'get': _get,
            'set': _set
        };
    }

    /**
     * Creates or replaces a read-write-property in a given scope object, especially for non-writable properties.
     * This also works for built-in host objects (non-DOM objects), e.g. navigator.
     * Optional an initial value can be passed, otherwise the current value of the object-property will be set.
     *
     * @param {Object} objBase  e.g. window
     * @param {String} objScopeName    e.g. "navigator"
     * @param {String} propName    e.g. "userAgent"
     * @param {Any} [initValue] (optional)   e.g. window.navigator.userAgent
     */
    makePropertyWritable (objBase, objScopeName, propName, initValue) {
        var newProp,
            initObj;

        if (objBase && objScopeName in objBase && propName in objBase[objScopeName]) {
            if (typeof initValue === 'undefined') {
                initValue = objBase[objScopeName][propName];
            }

            newProp = this.createProperty(initValue);

            try {
                Object.defineProperty(objBase[objScopeName], propName, newProp);
            } catch (e) {
                initObj = {};
                initObj[propName] = newProp;
                try {
                    objBase[objScopeName] = Object.create(objBase[objScopeName], initObj);
                } catch (e) {
                    // Workaround, but necessary to overwrite native host objects
                }
            }
        }
    }

    /**
     * @see https://deviceatlas.com/blog/list-of-user-agent-strings
     */
    getAgents () {
        return {
            //phones
            'GalaxyS9': {
                x: 360,
                y: 740,
                agent: 'Mozilla/5.0 (Linux; Android 8.0.0; SM-G960F Build/R16NW) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.84 Mobile Safari/537.36'
            },
            'GalaxyS8': {
                x: 360,
                y: 740,
                agent: 'Mozilla/5.0 (Linux; Android 7.0; SM-G892A Build/NRD90M; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/60.0.3112.107 Mobile Safari/537.36'
            },
            'iPhoneX': {
                x: 375,
                y: 812,
                agent: 'Mozilla/5.0 (iPhone; CPU iPhone OS 11_0 like Mac OS X) AppleWebKit/604.1.38 (KHTML, like Gecko) Version/11.0 Mobile/15A372 Safari/604.1'
            },
            'iPhone8': {
                x: 375,
                y: 667,
                agent: 'Mozilla/5.0 (iPhone; CPU iPhone OS 11_0 like Mac OS X) AppleWebKit/604.1.34 (KHTML, like Gecko) Version/11.0 Mobile/15A5341f Safari/604.1'
            },
            //tablets
            'GalaxyTabS3': {
                x: 375,
                y: 667,
                agent: 'Mozilla/5.0 (Linux; Android 7.0; SM-T827R4 Build/NRD90M) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.116 Safari/537.36'
            },
            'GalaxyTabA': {
                x: 375,
                y: 667,
                agent: 'Mozilla/5.0 (Linux; Android 5.0.2; SAMSUNG SM-T550 Build/LRX22G) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/3.3 Chrome/38.0.2125.102 Safari/537.36'
            },
            'iPadPro9.7': {
                x: 768,
                y: 1024,
                agent: 'Mozilla/5.0 (iPad; CPU OS 11_0 like Mac OS X) AppleWebKit/604.1.34 (KHTML, like Gecko) Version/11.0 Mobile/15A5341f Safari/604.1'
            },
            'iPadPro12.9': {
                x: 1024,
                y: 1366,
                agent: 'Mozilla/5.0 (iPad; CPU OS 11_0 like Mac OS X) AppleWebKit/604.1.34 (KHTML, like Gecko) Version/11.0 Mobile/15A5341f Safari/604.1'
            }
        };
    }

    setAgent (platform) {
        let agents = this.getAgents();
        if (!agents[platform]) {
            console.error('Invalid platform', platform);
            return;
        }
        this.makePropertyWritable(this.window, 'navigator', 'userAgent');
        this.window.navigator.userAgent = agents[platform].agent;
        this.window.userAgentX = agents[platform].x;
        this.window.userAgentY = agents[platform].y;

        console.log(this.window.navigator.userAgent);
    }

    set (platform, landscape) {
        if (platform === 'phone') {
            this.setAgent('GalaxyS9');
        }
        if (platform === 'tablet') {
            this.setAgent('iPadPro9.7');
        }
        if (landscape) {
            this.window.userAgentLandscape = true;
        }
    }

    discover () {
        let s = this.window.location.search;
        if (s.match(/\bphone\b/)) {
            this.setAgent('GalaxyS9');
        } else {
            if (s.match(/\btablet\b/)) {
                this.setAgent('iPadPro9.7');
            } else {
            }
        }

        if (s.match(/\blandscape\b/)) {
            this.window.userAgentLandscape = true;
        }
    }
}