Selectively escape or exclude from escaping HTML tags

escapeHTMLTags.js

/**
 * Slice an array every n element
 * @example
 * array_slice_every_n([1,2,3,4,5,6,7], 3)
 * //=> [[1,4,7],[2,5],[3,6]]
 */
function array_slice_every_n(array, n) {
    let subs = Array(n);
    const min_len = Math.floor(array.length / n);
    const rem = array.length - n * min_len;
    for (let m = 0; m < n; m++) {
        subs[m] = Array(min_len + (rem - m > 0 ? 1 : 0));
    }
    for (let i = 0; i < array.length; i++) {
        subs[i % n][Math.floor(i / n)] = array[i];
    }
    return subs;
}

function array_separate_odd_and_pair_indices(array) {
    const [odds, pairs] = array_slice_every_n(array, 2);
    return { odds, pairs };
}

function increment_wrap({low: lo, high: hi, index: i}) {
    return i >= hi ? lo : i + 1;
}

/**
 * Interleave arrays elements into one array
 * @example
 * arrays_interleave([1,2,3,4], "abcdefgh".split(''), "ABCDE".split(''))
 * //=> [1,"a","A" 2,"b","B",3,"c","C",4,"d","D","e","E","f","g", "h"]
 * @param {...[]} arrays
 */
function arrays_interleave(array_a, array_b) {
    var arrays = Array.prototype.slice.call(arguments, 0);
    var result = [];
    for (let i = 0; arrays.length; i = increment_wrap({low: 0, high: arrays.length - 1, index: i})) {
        if (arrays[i].length === 0) {
            arrays.splice(i, 1);
            i = i - 1;
        } else {
            result.push(arrays[i].shift());
        }
    }
    return result;
}

function escapeHTML(text) {
    const replacements = [
        { match: /&/g,  subst: "&amp;" },
        { match: /</g,  subst: "&lt;" },
        { match: />/g,  subst: "&gt;" },
        { match: /"/g,  subst: "&quot;" },
        { match: /'/g,  subst: "&#039;" },
        { match: /\//g, subst: "&#047;" },
    ];
    return replacements.reduce((p, { match, subst }) => p.replace(match, subst), text);
}

/**
 * @param {string} options.text - Raw HTML input
 * @param {string|string[]} options.tagNames - Name of the tag(s) to exclude or include in the escaping
 *  depending on the value of `exclude`
 * @param {boolean} [options.exclude=false] - If true: escape all but the selected tags, else escape only the
 *  selected tags
 * @return {string} escaped HTML
 */
function escapeHTMLTags({ text, tags: tagNames, exclude }) {
    const tagsRegexp = (tagNames) ?
        `(?:${(typeof tagNames === 'string' ? [tagNames] : tagNames).join('|')})` :
        '(?:\\w+)';
    const regexp = new RegExp(`(<\\s*/?\\s*${tagsRegexp}[^>]*\\s*>)`, 'ig');

    /* Split text into selected tags and the rest: [text, tag, text, tag, ...] */
    let { odds: chunks, pairs: tags } = array_separate_odd_and_pair_indices(text.split(regexp));
    
    if (exclude) { /* If in exclude tags mode, we escape all the rest */
        chunks = chunks.map(escapeHTML);
    } else { /* else escape only the selected tags */
        tags = tags.map(escapeHTML);
    }

    return arrays_interleave(chunks, tags).join("");
}