config.json

{
  "autoprefixer": {
    "browsers": ["last 2 versions"]
  },
  "stylelint": {
    "reporters": [{ "formatter": "string", "console": "true" }]
  },
  "uglify": { "preserveComments": "some" },
  "jshint_reporter": "jshint-stylish",
  "sorting": {
    "sort-order": [
      [
        "font",
        "font-family",
        "font-size",
        "font-weight",
        "font-style",
        "font-variant",
        "font-size-adjust",
        "font-stretch",
        "font-effect",
        "font-emphasize",
        "font-emphasize-position",
        "font-emphasize-style",
        "font-smooth",
        "line-height"
      ],
      [
        "position",
        "z-index",
        "top",
        "right",
        "bottom",
        "left"
      ],
      [
        "display",
        "visibility",
        "float",
        "clear",
        "overflow",
        "overflow-x",
        "overflow-y",
        "-ms-overflow-x",
        "-ms-overflow-y",
        "clip",
        "zoom",
        "flex-direction",
        "flex-order",
        "flex-pack",
        "flex-align"
      ],
      [
        "-webkit-box-sizing",
        "-moz-box-sizing",
        "box-sizing",
        "width",
        "min-width",
        "max-width",
        "height",
        "min-height",
        "max-height",
        "margin",
        "margin-top",
        "margin-right",
        "margin-bottom",
        "margin-left",
        "padding",
        "padding-top",
        "padding-right",
        "padding-bottom",
        "padding-left"
      ],
      [
        "table-layout",
        "empty-cells",
        "caption-side",
        "border-spacing",
        "border-collapse",
        "list-style",
        "list-style-position",
        "list-style-type",
        "list-style-image"
      ],
      [
        "content",
        "quotes",
        "counter-reset",
        "counter-increment",
        "resize",
        "cursor",
        "-webkit-user-select",
        "-moz-user-select",
        "-ms-user-select",
        "user-select",
        "nav-index",
        "nav-up",
        "nav-right",
        "nav-down",
        "nav-left",
        "-webkit-transition",
        "-moz-transition",
        "-ms-transition",
        "-o-transition",
        "transition",
        "-webkit-transition-delay",
        "-moz-transition-delay",
        "-ms-transition-delay",
        "-o-transition-delay",
        "transition-delay",
        "-webkit-transition-timing-function",
        "-moz-transition-timing-function",
        "-ms-transition-timing-function",
        "-o-transition-timing-function",
        "transition-timing-function",
        "-webkit-transition-duration",
        "-moz-transition-duration",
        "-ms-transition-duration",
        "-o-transition-duration",
        "transition-duration",
        "-webkit-transition-property",
        "-moz-transition-property",
        "-ms-transition-property",
        "-o-transition-property",
        "transition-property",
        "-webkit-transform",
        "-moz-transform",
        "-ms-transform",
        "-o-transform",
        "transform",
        "-webkit-transform-origin",
        "-moz-transform-origin",
        "-ms-transform-origin",
        "-o-transform-origin",
        "transform-origin",
        "-webkit-animation",
        "-moz-animation",
        "-ms-animation",
        "-o-animation",
        "animation",
        "-webkit-animation-name",
        "-moz-animation-name",
        "-ms-animation-name",
        "-o-animation-name",
        "animation-name",
        "-webkit-animation-duration",
        "-moz-animation-duration",
        "-ms-animation-duration",
        "-o-animation-duration",
        "animation-duration",
        "-webkit-animation-play-state",
        "-moz-animation-play-state",
        "-ms-animation-play-state",
        "-o-animation-play-state",
        "animation-play-state",
        "-webkit-animation-timing-function",
        "-moz-animation-timing-function",
        "-ms-animation-timing-function",
        "-o-animation-timing-function",
        "animation-timing-function",
        "-webkit-animation-delay",
        "-moz-animation-delay",
        "-ms-animation-delay",
        "-o-animation-delay",
        "animation-delay",
        "-webkit-animation-iteration-count",
        "-moz-animation-iteration-count",
        "-ms-animation-iteration-count",
        "-o-animation-iteration-count",
        "animation-iteration-count",
        "-webkit-animation-direction",
        "-moz-animation-direction",
        "-ms-animation-direction",
        "-o-animation-direction",
        "animation-direction",
        "text-align",
        "-webkit-text-align-last",
        "-moz-text-align-last",
        "-ms-text-align-last",
        "text-align-last",
        "vertical-align",
        "white-space",
        "text-decoration",
        "text-emphasis",
        "text-emphasis-color",
        "text-emphasis-style",
        "text-emphasis-position",
        "text-indent",
        "-ms-text-justify",
        "text-justify",
        "letter-spacing",
        "word-spacing",
        "-ms-writing-mode",
        "text-outline",
        "text-transform",
        "text-wrap",
        "text-overflow",
        "-ms-text-overflow",
        "text-overflow-ellipsis",
        "text-overflow-mode",
        "-ms-word-wrap",
        "word-wrap",
        "word-break",
        "-ms-word-break",
        "-moz-tab-size",
        "-o-tab-size",
        "tab-size",
        "-webkit-hyphens",
        "-moz-hyphens",
        "hyphens",
        "pointer-events"
      ],
      [
        "opacity",
        "filter:progid:DXImageTransform.Microsoft.Alpha(Opacity",
        "-ms-filter:\\'progid:DXImageTransform.Microsoft.Alpha",
        "-ms-interpolation-mode",
        "color",
        "border",
        "border-width",
        "border-style",
        "border-color",
        "border-top",
        "border-top-width",
        "border-top-style",
        "border-top-color",
        "border-right",
        "border-right-width",
        "border-right-style",
        "border-right-color",
        "border-bottom",
        "border-bottom-width",
        "border-bottom-style",
        "border-bottom-color",
        "border-left",
        "border-left-width",
        "border-left-style",
        "border-left-color",
        "-webkit-border-radius",
        "-moz-border-radius",
        "border-radius",
        "-webkit-border-top-left-radius",
        "-moz-border-radius-topleft",
        "border-top-left-radius",
        "-webkit-border-top-right-radius",
        "-moz-border-radius-topright",
        "border-top-right-radius",
        "-webkit-border-bottom-right-radius",
        "-moz-border-radius-bottomright",
        "border-bottom-right-radius",
        "-webkit-border-bottom-left-radius",
        "-moz-border-radius-bottomleft",
        "border-bottom-left-radius",
        "-webkit-border-image",
        "-moz-border-image",
        "-o-border-image",
        "border-image",
        "-webkit-border-image-source",
        "-moz-border-image-source",
        "-o-border-image-source",
        "border-image-source",
        "-webkit-border-image-slice",
        "-moz-border-image-slice",
        "-o-border-image-slice",
        "border-image-slice",
        "-webkit-border-image-width",
        "-moz-border-image-width",
        "-o-border-image-width",
        "border-image-width",
        "-webkit-border-image-outset",
        "-moz-border-image-outset",
        "-o-border-image-outset",
        "border-image-outset",
        "-webkit-border-image-repeat",
        "-moz-border-image-repeat",
        "-o-border-image-repeat",
        "border-image-repeat",
        "outline",
        "outline-width",
        "outline-style",
        "outline-color",
        "outline-offset",
        "background",
        "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader",
        "background-color",
        "background-image",
        "background-repeat",
        "background-attachment",
        "background-position",
        "background-position-x",
        "-ms-background-position-x",
        "background-position-y",
        "-ms-background-position-y",
        "-webkit-background-clip",
        "-moz-background-clip",
        "background-clip",
        "background-origin",
        "-webkit-background-size",
        "-moz-background-size",
        "-o-background-size",
        "background-size",
        "box-decoration-break",
        "-webkit-box-shadow",
        "-moz-box-shadow",
        "box-shadow",
        "filter:progid:DXImageTransform.Microsoft.gradient",
        "-ms-filter:\\'progid:DXImageTransform.Microsoft.gradient",
        "text-shadow"
      ]
    ]
  }
}

files.js

var paths = {
  css: {
    src: './css/src/',
    dist: './css/'
  },
  js: {
    src: './js/src/',
    dist: './js/'
  },
  jshint: './',
  maps: './css/src/maps/'
}

var globs = {
  js: [
    paths.js.src + 'map.js',
    paths.js.src + 'main.js'
  ],
  js_dist: {
    original: 'app.js',
    minified: 'app.min.js'
  },
  jshint: '.jshintrc',
  css: [
    paths.css.src + 'style.css'
  ],
  css_raw: [
    paths.css.src + '*.css'
  ],
  maps: [
    'config.yml',
    'breakpoints.yml',
    'colors.yml',
    'icons.yml',
    'fonts.yml'
  ]
};

module.exports = {
  paths: paths,
  globs: globs
};

gulpfile.js

var config = require('./gulp/config.json');
var files = require('./gulp/files');
var gulp = require('gulp');
var postcss = require('gulp-postcss');
var sourcemaps = require('gulp-sourcemaps');
var autoprefixer = require('autoprefixer');
var cssnano = require('cssnano');
var sorting = require('postcss-sorting');
var atImport = require('postcss-import');
var precss = require('precss');
var gulpStylelint = require('gulp-stylelint');
var calc = require('postcss-calc');
var simpleVars = require('postcss-simple-vars');
var postcssnested = require('postcss-nested');
var map = require('postcss-map');
var cssstats = require('cssstats');
var rename = require('gulp-rename');
var jshint = require('gulp-jshint');
var uglify = require('gulp-uglify');
var concat = require('gulp-concat');
var sizereport = require('gulp-sizereport');

gulp.task('default', ['css', 'js']);

gulp.task('lint-css', function () {
  return gulp.src(files.globs.css_raw)
    .pipe(sourcemaps.init())
    .pipe(gulpStylelint(config.stylelint));
});

gulp.task('css', ['lint-css'], function () {
  var processors = [
    atImport(),
    precss(),
    map({ basePath: files.paths.maps, maps: files.globs.maps }),
    postcssnested(),
    calc(),
    simpleVars(),
    autoprefixer(config.autoprefixer),
    sorting(config.sorting),
    cssnano()
  ];

  return gulp.src(files.globs.css)
    .pipe(sourcemaps.init())
    .pipe(postcss(processors))
    .pipe(sourcemaps.write('.'))
    .pipe(gulp.dest(files.paths.css.dist))
    .pipe(sizereport());
});

gulp.task('lint-js', function() {
  return gulp.src(files.globs.js)
    .pipe(jshint(files.paths.jshint + files.globs.jshint))
    .pipe(jshint.reporter(config.jshint_reporter));
});

gulp.task('js', ['lint-js'], function() {
  return gulp.src(files.globs.js)
    .pipe(concat(files.globs.js_dist.original))
    .pipe(gulp.dest(files.paths.js.dist))
    .pipe(rename(files.globs.js_dist.minified))
    .pipe(uglify(config.uglify))
    .pipe(gulp.dest(files.paths.js.dist))
    .pipe(sizereport());
});