import * as gulp from 'gulp'; import gulpSass = require('gulp-sass'); import sassVariables = require('gulp-sass-variables'); const IS_DEVELOPMENT = true; gulp.task('styles', () => { return gulp.src('./src/scss/master.scss') .pipe(sassVariables({ $IS_DEVELOPMENT: IS_DEVELOPMENT })) .pipe(gulpSass()) .pipe(gulp.dest('./dist/css')); });