Gulpjs combine two tasks into a single task

Question

I currently have two tasks, that both compile sass files. I would still like to concat the two directories into separate files but it seems that it would be more maintainable if I could simply create a 'sass' task that would be responsible for all of the sass compilation.

// Compile Our Sass
gulp.task('bootstrap-sass', function() {
  return gulp.src('./public/bower/bootstrap-sass/lib/*.scss')
    .pipe(sass())
    .pipe(contact('bootstrap.css'))
    .pipe(gulp.dest('./public/dist/css'));
});

gulp.task('site-sass', function() {
  return gulp.src('./public/app/scss/*.scss')
    .pipe(sass())
    .pipe(contact('site.css'))
    .pipe(gulp.dest('./public/dist/css'));
});

UPDATE:

I've tried this:

// Compile Our Sass
gulp.task('sass', function() {
  var bootstrap = function() {
    return gulp
      .src('./public/bower/bootstrap-sass/lib/*.scss')
      .pipe(sass())
      .pipe(concat('bootstrap.css'))
      .pipe(gulp.dest('./public/dist/css'));
  };

  var site = function() {
    return gulp
      .src('./public/src/scss/*.scss')
      .pipe(sass())
      .pipe(concat('site.css'))
      .pipe(gulp.dest('./public/dist/css'));
  };

  return Promise.all([bootstrap, site]);
});

But now it appears that neither file is being compiled. Any suggestions on what I am doing wrong?

Answer 1

Have you tried using merge-stream?

merge = require('merge-stream');
// Compile Our Sass
gulp.task('sass', function() {
  var bootstrap = gulp
      .src('./public/bower/bootstrap-sass/lib/*.scss')
      .pipe(sass())
      .pipe(concat('bootstrap.css'))
      .pipe(gulp.dest('./public/dist/css'));

  var site = gulp
      .src('./public/src/scss/*.scss')
      .pipe(sass())
      .pipe(concat('site.css'))
      .pipe(gulp.dest('./public/dist/css'));

  return merge(bootstrap, site);

});

See https://blog.mariusschulz.com/2015/05/02/merging-two-gulp-streams for more details

Answer 2

In Gulp version 4, we have parallel, so you can do:

// Compile Our Sass
gulp.task('bootstrap-sass', function() {
  return gulp.src('./public/bower/bootstrap-sass/lib/*.scss')
    .pipe(sass())
    .pipe(concat('bootstrap.css'))
    .pipe(gulp.dest('./public/dist/css'));
});

gulp.task('site-sass', function() {
  return gulp.src('./public/app/scss/*.scss')
    .pipe(sass())
    .pipe(concat('site.css'))
    .pipe(gulp.dest('./public/dist/css'));
});

gulp.task('sass', gulp.parallel('bootstrap-sass', 'site-sass')); // Combine

You can also write it as a single task by doing:

gulp.task('sass', gulp.parallel(
  function() {
      return gulp.src('./public/bower/bootstrap-sass/lib/*.scss')
        .pipe(sass())
        .pipe(concat('bootstrap.css'))
        .pipe(gulp.dest('./public/dist/css'));
  },
  function() {
      return gulp.src('./public/app/scss/*.scss')
        .pipe(sass())
        .pipe(concat('site.css'))
        .pipe(gulp.dest('./public/dist/css'));
  }));

I prefer the first method because it is easier to maintain

Answer 3

I just found a gulp plugin called gulp-all and tried it. It's simple to use.

https://www.npmjs.com/package/gulp-all

The documentation of the package says:

var all = require('gulp-all')

var styl_dir = 'path/to/styles/dir'
var js_dir   = 'path/to/scripts/dir'

function build() {
    return all(
        gulp.src(styl_dir + '/**/*')
            // build Styles 
            .pipe(gulp.dest('dist_dir')),
        gulp.src(js_dir + '/**/*')
            // build Scripts 
            .pipe(gulp.dest('dist_dir'))
    )
}

gulp.task('build', build);

also you can put subtasks in an array:

var scriptBundles = [/*...*/]

function build(){
    var subtasks = scriptBundles.map(function(bundle){
        return gulp.src(bundle.src).pipe(/* concat to bundle.target */)
    })
    return all(subtasks)
}

Answer 4

It works.

var task1 = gulp.src(...)...
var task2 = gulp.src(...)...
return [task1, task2];

Answer 5

Its also possible, to create another task to compile other tasks by passing an array of task names like this:

gulp.task('sass-file-one', function () {
     console.log('compiled sass-file-one')
});
gulp.task('sass-file-two', function () {
     console.log('compiled sass-file-two')
});

gulp.task('compile-all-sass', ['sass-file-one','sass-file-two']);

then you can simply run gulp compile-all-sass

Answer 6

THE SOLUTION: call the functions!!!

return Promise.all([bootstrap(), site()])

Be aware of the parens bootstrap(), site() so they return a promise :)