getChildFromSinglePath.ts

import {getChildren} from './getChildren.js';

export function getChildFromSinglePath(el: HTMLElement, token: string){
    let idx = 0;
    let nonIndexedToken = token;
    if(token === '..'){
        // this.$0 = this.$0.parentElement;
        // return this.$0;
        return el.parentNode !== null ? el.parentNode : (<any>el).host;
    }
    if(token.endsWith(']')){
        const posOfOpen = token.indexOf('[');
        const indxString = token.substring(posOfOpen + 1, token.length - 1);
        idx = parseInt(indxString);
        nonIndexedToken = token.substring(0, posOfOpen);
    }
    //const children = this.$0.querySelectorAll(':scope > ' + nonIndexedToken);
    const matchingNodes = [];
    getChildren(el).forEach((child : HTMLElement) =>{
        if(child.matches){
            const iPosStart =nonIndexedToken.indexOf('#"');
            if(iPosStart !== -1){
                const iPosEnd = nonIndexedToken.indexOf('"', iPosStart + 2);
                const id = nonIndexedToken.substring(iPosStart + 2, iPosEnd);
                if(child.id === id){
                    matchingNodes.push(child);
                }
            }else if(child.matches(nonIndexedToken)){
                matchingNodes.push(child);
            }
        }
    });
    return  matchingNodes[idx] as HTMLElement;
}