@adguard/agtree/dist/ast-utils/scriptlets.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 { EMPTY } from '../utils/constants.js';
import { QuoteUtils } from '../utils/quotes.js';
import { isUndefined, isNull } from '../utils/type-guards.js';

/**
 * @file Utility functions for working with scriptlet nodes.
 */
/**
 * Get name of the scriptlet from the scriptlet node.
 *
 * @param scriptletNode Scriptlet node to get name of.
 *
 * @returns Name of the scriptlet.
 *
 * @throws If the scriptlet is empty.
 */
function getScriptletName(scriptletNode) {
    if (scriptletNode.children.length === 0) {
        throw new Error('Empty scriptlet');
    }
    return scriptletNode.children[0]?.value ?? EMPTY;
}
/**
 * Transform the nth argument of the scriptlet node.
 *
 * @param scriptletNode Scriptlet node to transform argument of.
 * @param index Index of the argument to transform (index 0 is the scriptlet name).
 * @param transform Function to transform the argument.
 */
function transformNthScriptletArgument(scriptletNode, index, transform) {
    const child = scriptletNode.children[index];
    if (!isUndefined(child)) {
        const transformed = transform(child?.value ?? null);
        if (isNull(transformed)) {
            // eslint-disable-next-line no-param-reassign
            scriptletNode.children[index] = null;
            return;
        }
        if (isNull(child)) {
            // eslint-disable-next-line no-param-reassign
            scriptletNode.children[index] = {
                type: 'Value',
                value: transformed,
            };
            return;
        }
        child.value = transformed;
    }
}
/**
 * Transform all arguments of the scriptlet node.
 *
 * @param scriptletNode Scriptlet node to transform arguments of.
 * @param transform Function to transform the arguments.
 */
function transformAllScriptletArguments(scriptletNode, transform) {
    for (let i = 0; i < scriptletNode.children.length; i += 1) {
        transformNthScriptletArgument(scriptletNode, i, transform);
    }
}
/**
 * Set name of the scriptlet.
 * Modifies input `scriptletNode` if needed.
 *
 * @param scriptletNode Scriptlet node to set name of.
 * @param name Name to set.
 */
function setScriptletName(scriptletNode, name) {
    transformNthScriptletArgument(scriptletNode, 0, () => name);
}
/**
 * Set quote type of the scriptlet parameters.
 *
 * @param scriptletNode Scriptlet node to set quote type of.
 * @param quoteType Preferred quote type.
 */
function setScriptletQuoteType(scriptletNode, quoteType) {
    // null is a special value that means "no value", but we can't change its quote type,
    // so we need to convert it to empty string
    transformAllScriptletArguments(scriptletNode, (value) => QuoteUtils.setStringQuoteType(value ?? EMPTY, quoteType));
}

export { getScriptletName, setScriptletName, setScriptletQuoteType, transformAllScriptletArguments, transformNthScriptletArgument };