uBlock/platform/mv3/scriptlets/no-fetch-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-fetch-if

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

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

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

// $rulesetId$

const argsList = self.$argsList$;

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

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

const scriptlet = (
    conditions = ''
) => {
    const needles = [];
    for ( const condition of conditions.split(/\s+/) ) {
        if ( condition === '' ) { continue; }
        const pos = condition.indexOf(':');
        let key, value;
        if ( pos !== -1 ) {
            key = condition.slice(0, pos);
            value = condition.slice(pos + 1);
        } else {
            key = 'url';
            value = condition;
        }
        if ( value === '' ) {
            value = '^';
        } else if ( value.startsWith('/') && value.endsWith('/') ) {
            value = value.slice(1, -1);
        } else {
            value = value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
        }
        needles.push({ key, re: new RegExp(value) });
    }
    self.fetch = new Proxy(self.fetch, {
        apply: function(target, thisArg, args) {
            let proceed = true;
            try {
                let details;
                if ( args[0] instanceof self.Request ) {
                    details = args[0];
                } else {
                    details = Object.assign({ url: args[0] }, args[1]);
                }
                const props = new Map();
                for ( const prop in details ) {
                    let v = details[prop];
                    if ( typeof v !== 'string' ) {
                        try { v = JSON.stringify(v); }
                        catch(ex) { }
                    }
                    if ( typeof v !== 'string' ) { continue; }
                    props.set(prop, v);
                }
                proceed = needles.length === 0;
                for ( const { key, re } of needles ) {
                    if (
                        props.has(key) === false ||
                        re.test(props.get(key)) === false
                    ) {
                        proceed = true;
                        break;
                    }
                }
            } catch(ex) {
            }
            return proceed
                ? Reflect.apply(target, thisArg, args)
                : Promise.resolve(new Response());
        }
    });
};

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

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();

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

})();

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