update-local-script-rules.js

/**
 * By the rules of AMO and addons.opera.com we cannot use remote scripts (and our JS injection rules could be counted as remote scripts).
 * So what we do:
 * 1. We gather all current JS rules in the local_script_rules.json and load into the DEFAULT_SCRIPT_RULES object (see lib/utils/local-script-rules.js)
 * 2. We disable JS rules got from remote server
 * 3. We allow only custom rules got from the User filter (which user creates manually) or from this DEFAULT_SCRIPT_RULES object
 */

import fs from 'fs';
import gulp from 'gulp';
import { FILTERS_DEST, LAST_ADGUARD_FILTER_ID, LOCAL_SCRIPT_RULES_COMMENT } from './consts';

/**
 * @param arr - array with elements [{domains: '', script: ''}, ...]
 * @param domainsToCheck String
 * @param scriptToCheck String
 * @returns {boolean}
 */
const isInArray = (arr, domainsToCheck, scriptToCheck) => {
    for (let i = 0; i < arr.length; i += 1) {
        const element = arr[i];
        const { domains, script } = element;
        if (domains === domainsToCheck && script === scriptToCheck) {
            return true;
        }
    }
    return false;
};

const updateLocalScriptRules = (browser, done) => {
    const folder = FILTERS_DEST.replace('%browser', browser);
    const rules = {
        comment: LOCAL_SCRIPT_RULES_COMMENT,
        rules: [],
    };

    for (let i = 1; i <= LAST_ADGUARD_FILTER_ID; i += 1) {
        const filters = fs.readFileSync(`${folder}/filter_${i}.txt`).toString();
        const lines = filters.split('\n');

        for (let rule of lines) {
            rule = rule.trim();
            if (rule && rule[0] !== '!' && rule.indexOf('#%#') > -1) {
                let m = rule.split('#%#');
                m[0] = m[0] === '' ? '<any>' : m[0];
                // check that rule is not in array already
                if (!isInArray(rules.rules, m[0], m[1])) {
                    rules.rules.push({
                        domains: m[0],
                        script: m[1],
                    });
                }
            }
        }
    }

    fs.writeFileSync(FILTERS_DEST.replace('%browser', browser) + '/local_script_rules.json', JSON.stringify(rules, null, 4));

    return done();
};

const chromium = (done) => updateLocalScriptRules('chromium', done);
const edge = (done) => updateLocalScriptRules('edge', done);
const firefox = (done) => updateLocalScriptRules('firefox', done);
const operaBrowser = (done) => updateLocalScriptRules('opera', done);

export default gulp.series(chromium, edge, firefox, operaBrowser);