node-compile-execute-handlebars.js

/**
 * @desc    Compile and execute handlebars and populate dest dir with markup
 */
gulp.task('handlebars', function() {

    /**
     * @desc    File that contains data to be compile and executed by Handlebars
     * @type    {json}
     */
    var handlebarsContext = require('./src/data.json');

    /**
     * @desc    Compile handlebars template from specified path then execute with the data from the provided json source
     * @param   {string}     err    Error message
     * @param   {handlebars} source Handlebars template source
     */
    function compileAndExecuteHandlebars(err, source) {
        if (err) {
            return console.log(err);
        }

        var template = handlebars.compile(source);
        var markup = template(handlebarsContext);
        console.log('********** Handlebars template compile and executed **********');

        if (!fs.existsSync('./dist/')) {
            fs.mkdirSync('./dist/');
        }

        populateResult(markup);
    }

    /**
     * @desc    Write handlebars result markup file into the specified dir
     */
    function populateResult(markup) {
        fs.writeFile('./dist/index.html', markup, (err) => {
            if (err) throw err;
            console.log('********** Markup file saved **********');
        });
    }

    fs.readFile('./src/index.html', 'utf8', compileAndExecuteHandlebars);
});