gulpfile.js

/*global require*/
"use strict";

var gulp = require('gulp'),
    _ = require('lodash'),
    path = require('path'),
    data = require('gulp-data'),
    pug = require('gulp-pug'),
    prefix = require('gulp-autoprefixer'),
    sass = require('gulp-sass'),
    babel = require('gulp-babel'),
    browserSync = require('browser-sync'),
    watch = require('gulp-watch'),
    webpack = require('gulp-webpack'),
    webpackConfig = require('./webpack.config.js');

/*
 * Directories here
 */
var paths = {
    public: './public/',
    assets_src: './src/assets/',
    sass: './src/sass/',
    js_src: './src/js/**/*.js',
    css: './public/css/',
    js: './public/js/',
    data: './src/_data/'
};

/**
 * Compile .pug files and pass in data from json file
 * matching file name. index.pug - index.pug.json
 */
gulp.task('pug', function() {
    delete require.cache[require.resolve(paths.data + 'globals.pug.json')];
    var globals = require(paths.data + 'globals.pug.json');
    return gulp.src('./src/*.pug')
        .pipe(data(function(file) {
            delete require.cache[require.resolve(paths.data + path.basename(file.path) + '.json')];
            return _.merge({}, globals, require(paths.data + path.basename(file.path) + '.json'));
        }))
        .pipe(pug())
        .on('error', function(err) {
            process.stderr.write(err.message + '\n');
            this.emit('end');
        })
        .pipe(gulp.dest(paths.public));
});

/**
 * Compile .js files into public js directory
 */
gulp.task('js', () => {
    return gulp.src(paths.js_src)
        .pipe(webpack(webpackConfig))
        .pipe(gulp.dest(paths.js));
});

/**
 * Recompile .pug files and live reload the browser
 */
gulp.task('rebuild', ['pug', 'js'], function() {
    browserSync.reload();
});

/**
 * Wait for pug and sass tasks, then launch the browser-sync Server
 */
gulp.task('browser-sync', ['sass', 'pug', 'js'], function() {
    browserSync({
        server: {
            baseDir: paths.public
        },
        notify: false
    });
});

/**
 * Compile .scss files into public css directory With autoprefixer no
 * need for vendor prefixes then live reload the browser.
 */
gulp.task('sass', function() {
    return gulp.src(paths.sass + '*.scss')
        .pipe(sass({
            includePaths: [paths.sass],
            outputStyle: 'compressed'
        }))
        .on('error', sass.logError)
        .pipe(prefix(['last 15 versions', '> 1%', 'ie 8', 'ie 7'], {
            cascade: true
        }))
        .pipe(gulp.dest(paths.css))
        .pipe(browserSync.reload({
            stream: true
        }));
});

/**
 * Copy assets to public dir
 */
gulp.task('assets', function() {
    return gulp.src(paths.assets_src + '**/*', {base: paths.assets_src})
        .pipe(gulp.dest(paths.public + 'assets/'));
});

/**
 * Watch scss files for changes & recompile
 * Watch .pug files run pug-rebuild then reload BrowserSync
 */
gulp.task('watch', function() {
    gulp.watch(paths.sass + '**/*.scss', ['sass']);
    gulp.src(paths.assets_src + '**/*', {base: paths.assets_src})
        .pipe(watch(paths.assets_src, {base: paths.assets_src}))
        .pipe(gulp.dest(paths.public + 'assets/'))
        .pipe(browserSync.reload({
            stream: true
        }));
    gulp.watch([paths.data + '**/*.json', './src/**/*.pug', paths.js_src], ['rebuild']);
});

// Build task compile sass and pug.
gulp.task('build', ['sass', 'pug', 'js', 'assets']);

/**
 * Default task, running just `gulp` will compile the sass,
 * compile the jekyll site, launch BrowserSync then watch
 * files for changes
 */
gulp.task('default', ['browser-sync', 'watch']);