unique-selector/lib/getCombinations.js

Given a DOM node, return a unique CSS selector matching only that element

'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});
exports.getCombinations = getCombinations;
/**
 * Recursively combinate items.
 * @param  { Array } result
 * @param  { Array } items
 * @param  { Array } data
 * @param  { Number } start
 * @param  { Number } end
 * @param  { Number } index
 * @param  { Number } k
 */
function kCombinations(result, items, data, start, end, index, k) {
    if (index === k) {
        result.push(data.slice(0, index).join(''));
        return;
    }

    for (var i = start; i <= end && end - i + 1 >= k - index; ++i) {
        data[index] = items[i];
        kCombinations(result, items, data, i + 1, end, index + 1, k);
    }
}

/**
 * Returns all the possible selector combinations
 * @param  { Array } items
 * @param  { Number } k
 * @return { Array }
 */
function getCombinations(items, k) {
    var result = [],
        n = items.length,
        data = [];

    for (var l = 1; l <= k; ++l) {
        kCombinations(result, items, data, 0, n - 1, 0, l);
    }

    return result;
}