@adguard/agtree/dist/parser/cosmetic/selector/handlers/complex-selector-handler.js

Tool set for working with adblock filter lists

/*
 * AGTree v4.1.1 (build date: Thu, 23 Apr 2026 09:15:37 GMT)
 * (c) 2026 Adguard Software Ltd.
 * Released under the MIT license
 * https://github.com/AdguardTeam/tsurlfilter/tree/master/packages/agtree#readme
 */
import { sprintf } from 'sprintf-js';
import { getFormattedTokenName } from '@adguard/css-tokenizer';
import { AdblockSyntaxError } from '../../../../errors/adblock-syntax-error.js';
import { CompoundSelectorHandler } from './compound-selector-handler.js';

/**
 * Handles complex selector parsing in selector list.
 */
class ComplexSelectorHandler {
    /**
     * Finishes the current complex selector by:
     * 1. Finishing current compound selector node via {@link CompoundSelectorHandler},
     * 2. Validating current complex selector node,
     * 3. Appending current complex selector node to the selector list node,
     * If `isEof` is `false`:
     * 4. Constructing next complex selector node.
     *
     * @param context Selector list parser context.
     * @param isEof Indicates whether the end of the file has been reached.
     *
     * @throws If the current compound / complex selector has no simple selectors / compound selectors.
     */
    static handle(context, isEof = true) {
        const { raw, options, baseOffset, stream, token, result, complexSelector, } = context;
        // Get current complex selector end token
        const currentEndToken = stream.lookbehindForNonWs();
        // Finish current compound selector node
        CompoundSelectorHandler.handle(context);
        // Throw error if current complex selector node has no compound selector nodes (empty)
        if (!currentEndToken || complexSelector.children.length === 0) {
            throw new AdblockSyntaxError(sprintf("Unexpected token '%s' with value '%s'", getFormattedTokenName(token.type), raw.slice(token.start, token.end)), baseOffset + token.start, baseOffset + token.end);
        }
        // Include current complex selector node end location if needed
        if (options.isLocIncluded) {
            complexSelector.end = baseOffset + currentEndToken.end;
        }
        // Append current complex selector node to selector list node
        result.children.push(complexSelector);
        // If EOF is reached, just return, as we don't need to construct a next complex selector node
        if (isEof) {
            return;
        }
        // Get next complex selector node start token
        const nextStartToken = stream.getOrFail();
        // Construct next complex selector node
        const nextComplexSelector = {
            type: 'ComplexSelector',
            children: [],
        };
        // Include next complex selector node start location if needed
        if (options.isLocIncluded) {
            nextComplexSelector.start = baseOffset + nextStartToken.start;
        }
        // Update context with new complex selector
        context.complexSelector = nextComplexSelector;
        // Reset type selector set tracker for new selector
        context.isTypeSelectorSet = false;
    }
}

export { ComplexSelectorHandler };