Stackoverflow #32253344

gulpfile.js

var cssTasks = function(filename) {
  "use strict";
    return lazypipe()
    .pipe(function() {
      return gulpif((!config.env || config.env !== 'dev') && !enabled.failStyleTask, plumber());
    })
    .pipe(function() {
      return gulpif((!config.env || config.env !== 'dev') && enabled.maps, sourcemaps.init());
    })
    .pipe(function() {
      return gulpif('*.less', less());
    })
    .pipe(function() {
      return gulpif('*.scss', sass({
        outputStyle: 'nested', // libsass doesn't support expanded yet
        precision: 10,
        includePaths: ['.'],
        errLogToConsole: !enabled.failStyleTask
      }));
    })
    .pipe(concat, filename)
    .pipe(function() {
      return gulpif(!config.env || config.env !== 'dev', autoprefixer({
        browsers: [
          'last 2 versions',
          'ie 8',
          'ie 9',
          'android 2.3',
          'android 4',
          'opera 12'
        ]
      }));
    })
    .pipe(function() {
        return gulpif(!config.env || config.env !== 'dev', minifyCss({
          advanced: false,
          rebase: false
        }));
    })
    .pipe(function() {
      return gulpif((!config.env || config.env !== 'dev') && enabled.rev, rev());
    })
    .pipe(function() {
      return gulpif((!config.env || config.env !== 'dev') && enabled.maps, sourcemaps.write('.'));
    })();
};


// ### Styles
// `gulp styles` - Compiles, combines, and optimizes Bower CSS and project CSS.
// By default this task will only log a warning if a precompiler error is
// raised. If the `--production` flag is set: this task will fail outright.
gulp.task('styles', ['wiredep'], function() {
    "use strict";
    var merged = merge();
  manifest.forEachDependency('css', function(dep) {
    var cssTasksInstance = cssTasks(dep.name);
    if (!enabled.failStyleTask) {
      cssTasksInstance.on('error', function(err) {
        console.error(err.message);
        this.emit('end');
      });
    }
    merged.add(gulp.src(dep.globs, {base: 'styles'})
      .pipe(cssTasksInstance));
  });
  return merged
    .pipe(writeToManifest('styles'));
});

// ### Fonts
// `gulp fonts` - Grabs all the fonts and outputs them in a flattened directory
// structure. See: https://github.com/armed/gulp-flatten
gulp.task('fonts', function() {
    "use strict";
  return gulp.src(globs.fonts)
    .pipe(flatten())
    .pipe(gulp.dest(path.dist + 'fonts'))
    .pipe(browserSync.stream());
});