Gulp plugin gulp-ruby-sass(https://github.com/sindresorhus/gulp-ruby-sass) giving not compiling, the error message in terminal coming like this
Error: must provide pattern
Here is the gulpfile.js details
var gulp = require('gulp'),
uglify = require('gulp-uglify'),
sass = require('gulp-ruby-sass');
gulp.task('styles', function (argument) {
gulp.src('sass/app.scss')
.pipe(sass())
.pipe(gulp.dest('css/'));
});