posthtml-external-link/dist/index.js

Add 'rel="external noopener nofollow"' and 'target="_blank"' to all external links [PostHTML Plugin]

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.posthtmlExternalLink = void 0;
function posthtmlExternalLink(config) {
    return function postHtmlExternalLinkPlugin(tree) {
        if (!config)
            return tree;
        tree.walk((node) => {
            if (node.tag
                && node.tag === 'a'
                && node.attrs
                && node.attrs.href) {
                if (config) {
                    const exclude = Array.isArray(config.exclude) ? config.exclude : [config.exclude];
                    if (!isExternalLink(node.attrs.href, exclude)) {
                        return node;
                    }
                }
                // :: append rels to the element's [rel] value.
                //    failsafes in case [rel] is not defined yet.
                const rels = node.attrs.rel
                    ? new Set(node.attrs.rel.split(/\s+/))
                    : new Set();
                // config.noreferrer && rels.add('noreferrer');
                if (config.noreferrer)
                    rels.add('noreferrer');
                rels.add('noopener');
                rels.add('nofollow');
                rels.add('external');
                node.attrs.rel = Array.from(rels).join(' ');
                node.attrs.target = '_blank';
            }
            return node;
        });
        return tree;
    };
}
exports.posthtmlExternalLink = posthtmlExternalLink;
const cache = new Map();
function cacheApply(key, value) {
    var _a;
    if (cache.has(key))
        return (_a = cache.get(key)) !== null && _a !== void 0 ? _a : false;
    if (typeof value === 'function')
        value = value();
    cache.set(key, value);
    return value;
}
function isExternalLink(input, exclude) {
    return cacheApply(input, () => {
        if (!input.startsWith('//')
            && !input.startsWith('http://')
            && !input.startsWith('https://')) {
            return false;
        }
        let urlObj;
        try {
            urlObj = new URL(input);
        }
        catch (_a) { }
        // urlObj will be undefined if "input" is an invalid URL
        if (!(urlObj instanceof URL)) {
            return false;
        }
        // handle mailto: javascript: vbscript: etc.
        if (urlObj.origin === 'null') {
            return false;
        }
        if (exclude) {
            for (const i of exclude) {
                if (urlObj.hostname === i) {
                    return false;
                }
            }
        }
        if (urlObj.hostname !== input) {
            return true;
        }
        return false;
    });
}