Migrate to PostCSS 8

Author: hudochenkov

README.md

@@ -19,7 +19,7 @@ Lint and autofix style sheets order with [stylelint-order].
 ## Installation
 
 ```bash
-$ npm install postcss-sorting
+$ npm install --save-dev postcss postcss-sorting
 ```
 
 ## Options

index.js

@@ -1,15 +1,19 @@
-const postcss = require('postcss');
 const _ = require('lodash');
 
 const order = require('./lib/order');
 const propertiesOrder = require('./lib/properties-order');
 const validateOptions = require('./lib/validateOptions');
 
-module.exports = postcss.plugin('postcss-sorting', (opts) => {
-	return (css) => {
-		plugin(css, opts);
+module.exports = (opts) => {
+	return {
+		postcssPlugin: 'postcss-sorting',
+		Root(css) {
+			plugin(css, opts);
+		},
 	};
-});
+};
+
+module.exports.postcss = true;
 
 function plugin(css, opts) {
 	const validatedOptions = validateOptions(opts);

package-lock.json

@@ -23,8 +23,10 @@
     "!.DS_Store"
   ],
   "dependencies": {
-    "lodash": "^4.17.20",
-    "postcss": "^7.0.27"
+    "lodash": "^4.17.20"
+  },
+  "peerDependencies": {
+    "postcss": "^8.0.4"
   },
   "devDependencies": {
     "eslint": "^7.9.0",
@@ -36,6 +38,7 @@
     "jest": "^26.4.2",
     "jest-watch-typeahead": "^0.6.1",
     "lint-staged": "^10.4.0",
+    "postcss": "^8.0.4",
     "postcss-html": "^0.36.0",
     "postcss-jsx": "^0.36.4",
     "postcss-syntax": "^0.36.2",