uBlock/platform/mv3/scriptlets/no-addeventlistener-if.js

/*******************************************************************************

    uBlock Origin - a browser extension to block requests.
    Copyright (C) 2019-present Raymond Hill

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see {http://www.gnu.org/licenses/}.

    Home: https://github.com/gorhill/uBlock

    The scriptlets below are meant to be injected only into a
    web page context.
*/

/* jshint esversion:11 */

'use strict';

/******************************************************************************/

/// name no-addeventlistener-if
/// alias noaelif
/// alias addEventListener-defuser
/// alias aeld

/******************************************************************************/

// Important!
// Isolate from global scope
(function uBOL_noAddEventListenerIf() {

/******************************************************************************/

// $rulesetId$

const argsList = self.$argsList$;

const hostnamesMap = new Map(self.$hostnamesMap$);

/******************************************************************************/

const regexpFromArg = arg => {
    if ( arg === '' ) { return /^/; }
    if ( /^\/.+\/$/.test(arg) ) { return new RegExp(arg.slice(1,-1)); }
    return new RegExp(arg.replace(/[.*+?^${}()|[\]\\]/g, '\\$&'));
};

/******************************************************************************/

// Dependencies

const scriptletGlobals = new Map();

function safeSelf() {
    if ( scriptletGlobals.has('safeSelf') ) {
        return scriptletGlobals.get('safeSelf');
    }
    const safe = {
        'RegExp': self.RegExp,
        'RegExp_test': self.RegExp.prototype.test,
        'RegExp_exec': self.RegExp.prototype.exec,
        'addEventListener': self.EventTarget.prototype.addEventListener,
        'removeEventListener': self.EventTarget.prototype.removeEventListener,
    };
    scriptletGlobals.set('safeSelf', safe);
    return safe;
}

function runAt(fn, when) {
    const intFromReadyState = state => {
        const targets = {
            'loading': 1,
            'interactive': 2, 'end': 2, '2': 2,
            'complete': 3, 'idle': 3, '3': 3,
        };
        const tokens = Array.isArray(state) ? state : [ state ];
        for ( const token of tokens ) {
            const prop = `${token}`;
            if ( targets.hasOwnProperty(prop) === false ) { continue; }
            return targets[prop];
        }
        return 0;
    };
    const runAt = intFromReadyState(when);
    if ( intFromReadyState(document.readyState) >= runAt ) {
        fn(); return;
    }
    const onStateChange = ( ) => {
        if ( intFromReadyState(document.readyState) < runAt ) { return; }
        fn();
        safe.removeEventListener.apply(document, args);
    };
    const safe = safeSelf();
    const args = [ 'readystatechange', onStateChange, { capture: true } ];
    safe.addEventListener.apply(document, args);
}

/******************************************************************************/

const scriptlet = (
    arg1 = '',
    arg2 = ''
) => {
    const details = typeof arg1 !== 'object'
        ? { type: arg1, pattern: arg2 }
        : arg1;
    const { type = '', pattern = '' } = details;
    if ( typeof type !== 'string' ) { return; }
    if ( typeof pattern !== 'string' ) { return; }
    const reType = regexpFromArg(type);
    const rePattern = regexpFromArg(pattern);
    const trapEddEventListeners = ( ) => {
        const eventListenerHandler = {
            apply: function(target, thisArg, args) {
                let type, handler;
                try {
                    type = String(args[0]);
                    handler = String(args[1]);
                } catch(ex) {
                }
                if (
                    reType.test(type) === false ||
                    rePattern.test(handler) === false
                ) {
                    return target.apply(thisArg, args);
                }
            }
        };
        self.EventTarget.prototype.addEventListener = new Proxy(
            self.EventTarget.prototype.addEventListener,
            eventListenerHandler
        );
    };
    runAt(( ) => {
        trapEddEventListeners();
    }, details.runAt);
};

/******************************************************************************/

let hn;
try { hn = document.location.hostname; } catch(ex) { }
while ( hn ) {
    if ( hostnamesMap.has(hn) ) {
        let argsIndices = hostnamesMap.get(hn);
        if ( typeof argsIndices === 'number' ) { argsIndices = [ argsIndices ]; }
        for ( const argsIndex of argsIndices ) {
            const details = argsList[argsIndex];
            if ( details.n && details.n.includes(hn) ) { continue; }
            try { scriptlet(...details.a); } catch(ex) {}
        }
    }
    if ( hn === '*' ) { break; }
    const pos = hn.indexOf('.');
    if ( pos !== -1 ) {
        hn = hn.slice(pos + 1);
    } else {
        hn = '*';
    }
}

argsList.length = 0;
hostnamesMap.clear();

/******************************************************************************/

})();

/******************************************************************************/