Add a condition to run a gulp watch

I have a gulp watch task as following:

gulp.task("watch", () => {
  const watch = {
    'dev': [src_folder + '**/*.njk', src_js_folder + '**/*.js'],
    'css': [src_sass_folder + '**/*.scss']
  }
  gulp.watch(watch.dev, gulp.series("dev")).on("change", browserSync.reload);
  gulp.watch(watch.css, gulp.series("sass"));

});

gulp.task("dev", gulp.series("merge-json", "nunjucks", "sass", "js"));

So when there's any changes on *.sass files the sass task will run, and when there's changes on *.js and/or *.njk files the task dev will run.

The problem I'm having is when there are changes on *.sass, *.js and/or *.njk at the same time, the sass task will run twice in this case.

How can I skip the gulp.watch(watch.css, gulp.series("sass")); when the gulp.watch(watch.dev, gulp.series("dev")).on("change", browserSync.reload); is already run.

from Add a condition to run a gulp watch