upgrade gulp

gulpfile.js

@@ -1,21 +1,20 @@
 'use strict';
 
-var gulp = require('gulp');
+var { src, dest, series } = require('gulp');
 var postcss = require('gulp-postcss');
 var cssmin = require('gulp-cssmin');
 var salad = require('postcss-salad')(require('./salad.config.json'));
 
-gulp.task('compile', function() {
-  return gulp.src('./src/*.css')
+function compile() {
+  return src('./src/*.css')
     .pipe(postcss([salad]))
     .pipe(cssmin())
-    .pipe(gulp.dest('./lib'));
-});
-
-gulp.task('copyfont', function() {
-  return gulp.src('./src/fonts/**')
+    .pipe(dest('./lib'));
+}
+function copyfont() {
+  return src('./src/fonts/**')
     .pipe(cssmin())
-    .pipe(gulp.dest('./lib/fonts'));
-});
+    .pipe(dest('./lib/fonts'));
+}
 
-gulp.task('build', ['compile', 'copyfont']);
+exports.default = series(compile, copyfont)

package.json

@@ -9,7 +9,7 @@
     "src"
   ],
   "scripts": {
-    "build": "gulp build"
+    "build": "gulp"
   },
   "repository": {
     "type": "git",
@@ -26,7 +26,7 @@
   },
   "homepage": "https://github.com/ElementUI/theme-default#readme",
   "devDependencies": {
-    "gulp": "^3.9.1",
+    "gulp": "^4.0.2",
     "gulp-cssmin": "^0.1.7",
     "gulp-postcss": "^6.1.1",
     "postcss-salad": "^1.0.5"