Using gulp-sass

		
npm install --save-dev gulp-sass
		
		

gulpfile.js:

		
// including plugins
var gulp = require('gulp');
var sass = require("gulp-sass");

// task
gulp.task('compile-sass', function () {
    gulp.src('./Sass/one.sass') // path to your file
    .pipe(sass())
    .pipe(gulp.dest('path/to/destination'));
});
		
		

Run:

		
gulp compile-sass