md2html.js

const {readdir, readFile, realpathSync, stat, writeFile} = require('fs');
const showdown  = require('showdown');

const converter = new showdown.Converter();
converter.setFlavor('github');

const basePath = realpathSync('./');
console.log('--- md2html.js ---', basePath);

function md2Html(inFile, outFile) {
    if (!inFile.endsWith('.md')) return;
    readFile(inFile, 'utf8', (fsReadError, fileContent) => {
        if (!fsReadError) {
            console.log(inFile);
            const htmlContent = converter.makeHtml(fileContent);
            writeFile(outFile, htmlContent, (err) => err && console.error(err));
        } else {
            return console.error(inFile, fsReadError);
        }
    })
}

readdir(basePath, 'utf8', (fsDirError, fileNameList) => {
    if(!fsDirError) {
        fileNameList.forEach((file) => {
            const fileName = `${basePath}/${file}`;
            stat(fileName, (err, stats) => {
                if (stats.isDirectory()) {
                    readdir(fileName, 'utf8', (fsDirError, subFileNameList) => {
                        if(!fsDirError) {
                            subFileNameList.forEach((subFile) => {
                                const subFileName = `${fileName}/${subFile}`;
                                const outFile = `${basePath}/${subFile.replace('.md', '')}.${file}.html`;
                                md2Html(subFileName, outFile);
                            })
                        } else {
                            return console.error(fsDirError);
                        }
                    })
                } else {
                    md2Html(fileName, fileName.replace('.md', '.html'));
                }
            })
        })
    } else {
        return console.error(fsDirError);
    }
});