Gulp Browser Sync with sass compiling

sassBrowserSyncGulp.js

const gulp = require('gulp')
const browserSync = require('browser-sync').create()

gulp.task('browser-sync', ['sass'], () => {
    browserSync.init({
        server: {
            baseDir: "./"
        }
    })
    
    // watch the scss files for change to reload the server
    gulp.watch("app/scss/*.scss", ['sass'])
})

gulp.task('sass', function() {
    return gulp.src("app/scss/*.scss")
        .pipe(sass())
        .pipe(gulp.dest("app/css"))
        .pipe(browserSync.stream())
})