Alten technical challenge

tree_route_parser.js

const categories = [
    {
        name: 'category1',
        subcategories: [
            {
                name: 'category2',
                subcategories: []
            },
            {
                name: 'category3',
                subcategories: [
                    {
                        name: 'category4',
                        subcategories: []
                    }
                ]
            }
        ]
    },
    {
        name: 'category5',
        subcategories: []
    }
];

// Parse and store all possible routes to prevent tree traversing every time that `getCategoryPath` is called
const parsedCategories = [];

const traverseCategory = (categoryLevel, rootPath = '') => {
    const currentPath = `${rootPath}/${categoryLevel.name}`;

    if (categoryLevel.subcategories?.length > 0) {
        categoryLevel.subcategories.forEach((subcategory) => {
            traverseCategory(subcategory, currentPath);
        });
    }

    parsedCategories.push(currentPath);
};

categories.forEach((category) => {
    traverseCategory(category);
});

// At this time `parsedCategories` contains these values
/*
"/category1/category2"
"/category1/category3/category4"
"/category1/category3"
"/category1"
"/category5"
*/

// This function just needs to get the path from `parsedCategories`, a much simpler operation than finding it in the tree every time.
const getCategoryPath = (categories, categoryName) => {
    const path = parsedCategories.find((path) => path.endsWith(categoryName));
    return path ?? undefined;
};

// OUTPUT SAMPLES
console.log(getCategoryPath(categories, 'category4')); // should output: '/category1/category3/category4'
console.log(getCategoryPath(categories, 'category2')); // should output: '/category1/category2'
console.log(getCategoryPath(categories, 'category5')); // should output: '/category5'