Default gulp config for small WP / static sites

gulpfile.js

// npm i -D gulp gulp-sass gulp-clean-css gulp-watch gulp-sourcemaps gulp-rename gulp-autoprefixer gulp-nunjucks-render browser-sync
// requires gulp >= 4.0.0
var gulp = require('gulp');
var sass = require('gulp-sass');
var cleanCSS = require('gulp-clean-css');
var watch = require('gulp-watch');
var sourcemaps = require('gulp-sourcemaps');
var rename = require('gulp-rename');
var autoprefixer = require('gulp-autoprefixer');
var nunjucksRender = require('gulp-nunjucks-render');
var browserSync = require('browser-sync').create();

var reload = browserSync.reload;

var sassOptions = {
  errLogToConsole: true,
  outputStyle: 'compressed'
}

var cleanCSSOptions = {
  compatibility: 'ie8'
}

gulp.task('sass', function() {
  return gulp.src('sass/main.scss')
  .pipe(sourcemaps.init())
  .pipe(sass(sassOptions).on('error', sass.logError))
  .pipe(cleanCSS(cleanCSSOptions))
  .pipe(sourcemaps.write())
  .pipe(autoprefixer())
  .pipe(rename('style.css'))
  .pipe(gulp.dest('.'))
  .pipe(browserSync.stream());
});

gulp.task('nunjucks', function() {
  return gulp.src('templates/pages/**/*.nunjucks')
  .pipe(nunjucksRender({
      path: ['templates']
    }))
  .pipe(gulp.dest('.'))
  .pipe(browserSync.stream());
});

gulp.task('serve', gulp.series('sass', function () {
  browserSync.init({
    browser: "google chrome",
    proxy: "http://localhost/~martin/xx/", // useful for wp sites for instance
    port: 2345
  });

  gulp.watch('./sass/**/*.scss', gulp.series('sass'));
  gulp.watch('./templates/**/*.nunjucks', gulp.series('nunjucks'));
  gulp.watch('*.php').on('change', reload);
  gulp.watch('js/*.js').on('change', reload);
}));

gulp.task('default', gulp.series('serve'));