How to use the gulp-sass function in gulp-sass

run(watching = false) {
    // add debug for importing problems (can be very helpful)
    if(this.config.debug && this.config.options.importer === undefined) {
      this.config.options.importer = (url, prev, done) => {
        this.debug(`importing ${url} from ${prev}`)
        done({file: url})
      }
    }

    return this.gulp.src(this.config.source.glob, this.config.source.options)
      .pipe(gulpif(this.config.debug, debug(this.debugOptions())))
      .pipe(sourcemaps.init())
      .pipe(sass(this.config.options))
      .on('error', (error) => {
        this.notifyError(error, watching)
      })
      .pipe(autoprefixer(this.config.autoprefixer.options))
      .pipe(sourcemaps.write())
      .pipe(this.gulp.dest(this.config.dest))
      .pipe(this.browserSync.stream())
  }
}

gulp.task('sass', () => {
    const config = readConfig(`${CONFIG}/pleeease.json`);
    return gulp.src(`${SRC}/scss/style.scss`)
        .pipe(sassGlob())
        .pipe(sass())
        .pipe(pleeease(config))
        .pipe(postcss([
            require('postcss-assets')({
                loadPaths: [ 'img/' ],
                basePath: './public',
                // 相対位置の場合はコメントアウト
                relative: './css/',
            })
        ]))
        .pipe(gulp.dest(`${DEST}/css`));
});

gulp.task('sass:watch', () => {
  return gulp.src('./examples/assets/scss/*.scss')
    .pipe(watch('./examples/assets/scss/*.scss'))
    .pipe(sass())
    .pipe(gulp.dest('./examples/assets/css/'));
});

gulp.task("styles", () => {
    return gulp.src(paths.styles.src)
        .pipe(gulpif(!production, sourcemaps.init()))
        .pipe(plumber())
        .pipe(sass())
        .pipe(groupmedia())
        .pipe(gulpif(production, autoprefixer({
            cascade: false,
            grid: true
        })))
        .pipe(gulpif(production, mincss({
            compatibility: "ie8", level: {
                1: {
                    specialComments: 0,
                    removeEmpty: true,
                    removeWhitespace: true
                },
                2: {
                    mergeMedia: true,
                    removeEmpty: true,
                    removeDuplicateFontRules: true,

gulp.task('sass', ['clean:css'], () => {
  return gulp.src(localConfig.src, { base: localConfig.base })
    .pipe(plumber({ errorHandler }))
    .pipe(gulpif(taskOptions.lint, sassLint({
      config: '.sass-lint.yml'
    })))
    .pipe(gulpif(taskOptions.lint, sassLint.format()))
    .pipe(gulpif(taskOptions.lint, sassLint.failOnError()))
    .pipe(gulpif(taskOptions.sourcemaps, sourcemaps.init()))
      .pipe(filter('**/application.scss'))
      .pipe(sass(localConfig.sassOptions()))
      .pipe(autoprefixer({
        browsers: ['last 2 versions'],
        cascade: false
      }))
    .pipe(gulpif(taskOptions.sourcemaps, sourcemaps.write()))
    .pipe(gulp.dest(localConfig.dest));
});

if (!src) throw new Error('src not configured');
  if (!dest) throw new Error('dest not configured');

  let globs = src;
  let srcOptions = {};

  if (Array.isArray(src) && typeof src[1] === 'object') {
    [globs, srcOptions] = src;
  }

  if (sourceMap)
    return gulp
      .src(globs, srcOptions)
      .pipe(sourcemaps.init())
      .pipe(sass(options))
      .pipe(sourcemaps.write('.'))
      .pipe(gulp.dest(dest));

  return gulp
    .src(globs, srcOptions)
    .pipe(sass(options))
    .pipe(gulp.dest(dest));
};

gulp.task('transferCSS', () => {
  gulp
    .src('./src/css/pureFullPage.scss')
    .pipe(sass().on('error', sass.logError))
    .pipe(cleanCSS({ compatibility: '*' }))
    .pipe(rename('pureFullPage.min.css'))
    .pipe(gulp.dest('./dist'));
});

export function scss () {
  return gulp.src(PATHS.src_scss)
    .pipe(sass().on('error', sass.logError))
    .pipe(nano())
    .pipe(gulp.dest(PATHS.dest));
}

gulp.task('sass', () =>
  gulp.src(['./src/assets/sass/*.{scss,sass}'])
  .pipe(sass({ includePaths: ['bower_components', 'node_modules'], errLogToConsole: true }))
  .pipe(gulp.dest('./dist'))
  .pipe(rename({ suffix: '.min' }))
  .pipe(cleanCSS({ compatibility: 'ie8' }))
  .pipe(gulp.dest('./dist')),
);