ReferenceError: sass is not defined at Gulp.

Something like this will compile your Sass files:

'use strict';

 

var gulp = require('gulp');

var sass = require('gulp-sass');  // make sure you add this line

 

gulp.task('sass', function () {

  return gulp.src('./sass/**/*.scss')

    .pipe(sass().on('error', sass.logError))

    .pipe(gulp.dest('./css'));

});

 

gulp.task('sass:watch', function () {

  gulp.watch('./sass/**/*.scss', ['sass']);

});

You can also compile synchronously, doing something like this:

'use strict';

 

var gulp = require('gulp');

var sass = require('gulp-sass');  //make sure you add this line 

 

gulp.task('sass', function () {

  return gulp.src('./sass/**/*.scss')

    .pipe(sass.sync().on('error', sass.logError))

    .pipe(gulp.dest('./css'));

});

 

gulp.task('sass:watch', function () {

  gulp.watch('./sass/**/*.scss', ['sass']);

});

Options

Pass in options just like you would for node-sass; they will be passed along just as if you were using node-sass. Except for the data option which is used by gulp-sass internally. Using the file option is also unsupported and results in undefined behaviour that may change without notice.

For example:

gulp.task('sass', function () {

 return gulp.src('./sass/**/*.scss')

   .pipe(sass({outputStyle: 'compressed'}).on('error', sass.logError))

   .pipe(gulp.dest('./css'));

});

Source Maps

gulp-sass can be used in tandem with gulp-sourcemaps to generate source maps for the Sass to CSS compilation. You will need to initialize gulp-sourcemaps prior to running gulp-sass and write the source maps after.

var sourcemaps = require('gulp-sourcemaps');

 

gulp.task('sass', function () {

 return gulp.src('./sass/**/*.scss')

  .pipe(sourcemaps.init())

  .pipe(sass().on('error', sass.logError))

  .pipe(sourcemaps.write())

  .pipe(gulp.dest('./css'));

});

By default, gulp-sourcemaps writes the source maps inline in the compiled CSS files. To write them to a separate file, specify a path relative to the gulp.dest() destination in the sourcemaps.write() function.

var sourcemaps = require('gulp-sourcemaps');

gulp.task('sass', function () {

 return gulp.src('./sass/**/*.scss')

  .pipe(sourcemaps.init())

  .pipe(sass().on('error', sass.logError))

  .pipe(sourcemaps.write('./maps'))

  .pipe(gulp.dest('./css'));

});

Issues

gulp-sass is a very light-weight wrapper around node-sass, which in turn is a Node binding for libsass, which in turn is a port of Sass. Because of this, the issue you're having likely isn't a gulp-sass issue, but an issue with one of those three projects.

If you have a feature request/question how Sass works/concerns on how your Sass gets compiled/errors in your compiling, it's likely a libsass or Sass issue and you should file your issue with one of those projects.

If you're having problems with the options you're passing in, it's likely a node-sass or libsass issue and you should file your issue with one of those projects.

We may, in the course of resolving issues, direct you to one of these other projects. If we do so, please follow up by searching that project's issue queue (both open and closed) for your problem and, if it doesn't exist, filing an issue with them.