google-analytics.js

import {
    hit,
    noopFunc,
    noopNull,
    noopArray,
} from '../helpers';

/**
 * @redirect google-analytics
 *
 * @description
 * Mocks Google's Analytics and Tag Manager APIs.
 * Covers functionality of
 * the [obsolete googletagmanager-gtm redirect](https://github.com/AdguardTeam/Scriptlets/issues/127).
 *
 * Related UBO redirect resource:
 * https://github.com/gorhill/uBlock/blob/master/src/web_accessible_resources/google-analytics_analytics.js
 *
 * ### Examples
 *
 * ```adblock
 * ||google-analytics.com/analytics.js$script,redirect=google-analytics
 * ||googletagmanager.com/gtm.js$script,redirect=google-analytics
 * ```
 *
 * @added v1.0.10.
 */
export function GoogleAnalytics(source) {
    // eslint-disable-next-line func-names
    const Tracker = function () { }; // constructor
    const proto = Tracker.prototype;
    proto.get = noopFunc;
    proto.set = noopFunc;
    proto.send = noopFunc;

    const googleAnalyticsName = window.GoogleAnalyticsObject || 'ga';
    const queue = window[googleAnalyticsName]?.q;

    // a -- fake arg for 'ga.length < 1' antiadblock checking
    // eslint-disable-next-line no-unused-vars
    function ga(a) {
        const len = arguments.length;
        if (len === 0) {
            return;
        }
        // eslint-disable-next-line prefer-rest-params
        const lastArg = arguments[len - 1];

        let replacer;
        if (lastArg instanceof Object
            && lastArg !== null
            && typeof lastArg.hitCallback === 'function') {
            replacer = lastArg.hitCallback;
        } else if (typeof lastArg === 'function') {
            // https://github.com/AdguardTeam/Scriptlets/issues/98
            replacer = () => {
                lastArg(ga.create());
            };
        }

        try {
            setTimeout(replacer, 1);
            // eslint-disable-next-line no-empty
        } catch (ex) { }
    }

    ga.create = () => new Tracker();
    // https://github.com/AdguardTeam/Scriptlets/issues/134
    ga.getByName = () => new Tracker();
    ga.getAll = () => [new Tracker()];
    ga.remove = noopFunc;
    ga.loaded = true;
    window[googleAnalyticsName] = ga;

    if (Array.isArray(queue)) {
        const push = (arg) => {
            ga(...arg);
        };
        queue.push = push;
        queue.forEach(push);
    }

    const { dataLayer, google_optimize } = window; // eslint-disable-line camelcase
    if (dataLayer instanceof Object === false) {
        return;
    }

    if (dataLayer.hide instanceof Object
        && typeof dataLayer.hide.end === 'function') {
        dataLayer.hide.end();
    }

    /**
     * checks data object and delays callback
     *
     * @param {object|Array} dataObj gtag payload
     * @param {string} funcName callback prop name
     */
    const handleCallback = (dataObj, funcName) => {
        if (dataObj && typeof dataObj[funcName] === 'function') {
            setTimeout(dataObj[funcName]);
        }
    };

    if (typeof dataLayer.push === 'function') {
        dataLayer.push = (data) => {
            if (data instanceof Object) {
                handleCallback(data, 'eventCallback');
                // eslint-disable-next-line no-restricted-syntax, guard-for-in
                for (const key in data) {
                    handleCallback(data[key], 'event_callback');
                }
                // eslint-disable-next-line no-prototype-builtins
                if (!data.hasOwnProperty('eventCallback') && !data.hasOwnProperty('eventCallback')) {
                    [].push.call(window.dataLayer, data);
                }
            }
            if (Array.isArray(data)) {
                data.forEach((arg) => {
                    handleCallback(arg, 'callback');
                });
            }
            return noopFunc;
        };
    }

    // https://github.com/AdguardTeam/Scriptlets/issues/81
    // eslint-disable-next-line camelcase
    if (google_optimize instanceof Object && typeof google_optimize.get === 'function') {
        const googleOptimizeWrapper = {
            get: noopFunc,
        };

        window.google_optimize = googleOptimizeWrapper;
    }

    hit(source);
}

export const GoogleAnalyticsNames = [
    'google-analytics',
    'ubo-google-analytics_analytics.js',
    'google-analytics_analytics.js',
    // https://github.com/AdguardTeam/Scriptlets/issues/127
    'googletagmanager-gtm',
    'ubo-googletagmanager_gtm.js',
    'googletagmanager_gtm.js',
];

// eslint-disable-next-line prefer-destructuring
GoogleAnalytics.primaryName = GoogleAnalyticsNames[0];

GoogleAnalytics.injections = [
    hit,
    noopFunc,
    noopNull,
    noopArray,
];