@adguard/agtree/dist/parser/misc/modifier-list.js

Tool set for working with adblock filter lists

/*
 * AGTree v3.2.2 (build date: Tue, 08 Jul 2025 13:39:47 GMT)
 * (c) 2025 Adguard Software Ltd.
 * Released under the MIT license
 * https://github.com/AdguardTeam/tsurlfilter/tree/master/packages/agtree#readme
 */
import { MODIFIERS_SEPARATOR } from '../../utils/constants.js';
import { StringUtils } from '../../utils/string.js';
import { BaseParser } from '../base-parser.js';
import { defaultParserOptions } from '../options.js';
import { ModifierParser } from './modifier-parser.js';

/* eslint-disable no-param-reassign */
/**
 * `ModifierListParser` is responsible for parsing modifier lists. Please note that the name is not
 * uniform, "modifiers" are also known as "options".
 *
 * @see {@link https://kb.adguard.com/en/general/how-to-create-your-own-ad-filters#basic-rules-modifiers}
 * @see {@link https://kb.adguard.com/en/general/how-to-create-your-own-ad-filters#non-basic-rules-modifiers}
 * @see {@link https://help.eyeo.com/adblockplus/how-to-write-filters#options}
 */
class ModifierListParser extends BaseParser {
    /**
     * Parses the cosmetic rule modifiers, eg. `third-party,domain=example.com|~example.org`.
     *
     * _Note:_ you should remove `$` separator before passing the raw modifiers to this function,
     *  or it will be parsed in the first modifier.
     *
     * @param raw Raw input to parse.
     * @param options Global parser options.
     * @param baseOffset Starting offset of the input. Node locations are calculated relative to this offset.
     * @returns Parsed modifiers interface
     */
    static parse(raw, options = defaultParserOptions, baseOffset = 0) {
        const result = {
            type: 'ModifierList',
            children: [],
        };
        if (options.isLocIncluded) {
            result.start = baseOffset;
            result.end = baseOffset + raw.length;
        }
        let offset = StringUtils.skipWS(raw);
        let separatorIndex = -1;
        // Split modifiers by unescaped commas
        while (offset < raw.length) {
            // Skip whitespace before the modifier
            offset = StringUtils.skipWS(raw, offset);
            const modifierStart = offset;
            // Find the index of the first unescaped comma
            separatorIndex = StringUtils.findNextUnescapedCharacter(raw, MODIFIERS_SEPARATOR, offset);
            const modifierEnd = separatorIndex === -1
                ? raw.length
                : StringUtils.skipWSBack(raw, separatorIndex - 1) + 1;
            // Parse the modifier
            const modifier = ModifierParser.parse(raw.slice(modifierStart, modifierEnd), options, baseOffset + modifierStart);
            result.children.push(modifier);
            // Increment the offset to the next modifier (or the end of the string)
            offset = separatorIndex === -1 ? raw.length : separatorIndex + 1;
        }
        // Check if there are any modifiers after the last separator
        if (separatorIndex !== -1) {
            const modifierStart = StringUtils.skipWS(raw, separatorIndex + 1);
            result.children.push(ModifierParser.parse(raw.slice(modifierStart, raw.length), options, baseOffset + modifierStart));
        }
        return result;
    }
}

export { ModifierListParser };