gulp-sourcemaps.js

const gulpPostcss = require('gulp-postcss');
const postcssPartialImport = require('postcss-partial-import');
const postcssCssnext = require('postcss-cssnext');
const gulpRename = require('gulp-rename');
const gulpLivereload = require('gulp-livereload');
const gulpCssnano = require('gulp-cssnano');
const gulpif = require('gulp-if');
const sourcemaps = require('gulp-sourcemaps');            // <========================================


module.exports = function (gulp) {
  var processors = [
    postcssPartialImport({
      extension: '.pcss'
    }),
    postcssCssnext
  ];
  return gulp.src(SRC_PATH + '/styles/*.pcss')
    .pipe(gulpif(!global.dist, sourcemaps.init()))        // <========================================
    .pipe(gulpPostcss(processors))
    .pipe(gulpRename(function(filePath) {
      filePath.extname = '.css';
    }))
    .pipe(gulpif(global.dist, gulpCssnano()))
    .pipe(gulpif(!global.dist, sourcemaps.write('.')))    // <========================================
    .pipe(gulp.dest(TARGET_PATH + '/css'))
    .pipe(gulpLivereload())
  ;
};