Dragact/example/showdown/index.ts

const showdown = require('showdown');
const hljs = require('highlightjs');

var decodeHtml = require("html-encoder-decoder").decode;

function showdownHighlight() {
    return [{
        type: "output",
        filter: function filter(text: any, converter: any, options: any) {
            var left = "<pre><code\\b[^>]*>",
                right = "</code></pre>",
                flags = "g",
                replacement = function replacement(wholeMatch: any, match: any, left: any, right: any) {
                    match = decodeHtml(match);
                    var lang = (left.match(/class=\"([^ \"]+)/) || [])[1];
                    console.log(left + hljs.highlight(lang, match).value + right);
                    if (lang) {
                        return left + hljs.highlight(lang, match).value + right;
                    } else {
                        return left + hljs.highlightAuto(match).value + right;
                    }
                };

            return showdown.helper.replaceRecursiveRegExp(text, replacement, left, right, flags);
        }
    }];
};


export const convertor = new showdown.Converter({
    extensions: [showdownHighlight]
});