Gulp task for a static websites

gulpfile.js

var gulp         = require('gulp');
var connect      = require('gulp-connect');
var del          = require('del');
var sourcemaps   = require('gulp-sourcemaps');
var sass         = require('gulp-sass');
var autoprefixer = require('gulp-autoprefixer');
var uncss        = require('gulp-uncss');
var nano         = require('gulp-cssnano');
var htmlmin      = require('gulp-html-minifier');
var rev          = require('gulp-rev');
var revReplace   = require('gulp-rev-replace');

gulp.task('styles:dev', function () {
    return gulp.src('app/styles/app.scss', { base: 'app' })
        .pipe(sourcemaps.init())
        .pipe(sass())
        .pipe(sourcemaps.write({
            includeContent: false,
            sourceRoot: '/styles'
        }))
        .pipe(gulp.dest('tmp'))
        .pipe(connect.reload());
});

gulp.task('reload:html', function () {
    return gulp.src('app/**/*.html')
        .pipe(connect.reload());
});

gulp.task('reload:images', function () {
    return gulp.src('app/images/**/*')
        .pipe(connect.reload());
});

gulp.task('clean:dist', function () {
    return del([
        'dist/styles/*',
        'dist/images/*'
    ]);
});

gulp.task('styles:dist', ['clean:dist'], function () {
    return gulp.src('app/styles/app.scss', { base: 'app' })
        .pipe(sass())
        .pipe(autoprefixer())
        .pipe(uncss({
            html: ['app/index.html']
        }))
        .pipe(nano())
        .pipe(rev())
        .pipe(gulp.dest('dist'))
        .pipe(rev.manifest('dist/rev-minifest.json', {
            base: process.cwd() + '/dist',
            merge: true
        }))
        .pipe(gulp.dest('dist'));
});

gulp.task('images:dist', ['clean:dist'], function () {
    return gulp.src('app/images/**/*', { base: 'app' })
        .pipe(rev())
        .pipe(gulp.dest('dist'))
        .pipe(rev.manifest('dist/rev-minifest.json', {
            base: process.cwd() + '/dist',
            merge: true
        }))
        .pipe(gulp.dest('dist'));
});

gulp.task('html:dist', ['styles:dist', 'images:dist'], function () {
    var manifest = gulp.src('dist/rev-minifest.json');

    return gulp.src('app/*.html')
        .pipe(revReplace({ manifest: manifest }))
        .pipe(htmlmin({ collapseWhitespace: true }))
        .pipe(gulp.dest('dist'));
});

gulp.task('watch', function () {
    gulp.watch('app/styles/**/*.scss', ['styles:dev']);
    gulp.watch('app/**/*.html', ['reload:html']);
    gulp.watch('app/images/**/*', ['reload:images']);
});

gulp.task('build', ['clean:dist', 'styles:dist', 'images:dist', 'html:dist']);

gulp.task('serve', ['watch', 'styles:dev'], function () {
    connect.server({
        root: ['app', 'tmp'],
        livereload: true
    });
});

gulp.task('default', ['serve']);