Support PostCSS 8

Author: Semigradsky

.rollup.js

@@ -1,18 +1,19 @@
-import babel from 'rollup-plugin-babel';
+import babel from '@rollup/plugin-babel';
 
 export default {
 	input: 'index.js',
 	output: [
-		{ file: 'index.cjs.js', format: 'cjs', sourcemap: true },
-		{ file: 'index.es.mjs', format: 'es', sourcemap: true }
+		{ file: 'index.cjs.js', format: 'cjs', sourcemap: true, exports: 'default' },
+		{ file: 'index.es.mjs', format: 'es', sourcemap: true, exports: 'default' }
 	],
 	plugins: [
 		babel({
+			babelHelpers: 'bundled',
 			plugins: [
 				'@babel/plugin-syntax-dynamic-import'
 			],
 			presets: [
-				['@babel/env', { modules: false, targets: { node: 6 } }]
+				['@babel/env', { modules: false, targets: { node: 10 } }]
 			]
 		})
 	]

.travis.yml

@@ -3,7 +3,9 @@
 language: node_js
 
 node_js:
-  - 6
+  - 14
+  - 12
+  - 10
 
 install:
   - npm install --ignore-scripts

index.js

@@ -1,10 +1,9 @@
-import postcss from 'postcss';
 import getCustomMediaFromRoot from './lib/custom-media-from-root';
 import getCustomMediaFromImports from './lib/get-custom-media-from-imports';
 import transformAtrules from './lib/transform-atrules';
 import writeCustomMediaToExports from './lib/write-custom-media-to-exports';
 
-export default postcss.plugin('postcss-custom-media', opts => {
+const creator = opts => {
 	// whether to preserve custom media and at-rules using them
 	const preserve = 'preserve' in Object(opts) ? Boolean(opts.preserve) : false;
 
@@ -17,14 +16,21 @@ export default postcss.plugin('postcss-custom-media', opts => {
 	// promise any custom media are imported
 	const customMediaPromise = getCustomMediaFromImports(importFrom);
 
-	return async root => {
-		const customMedia = Object.assign(
-			await customMediaPromise,
-			getCustomMediaFromRoot(root, { preserve })
-		);
+	return {
+		postcssPlugin: 'postcss-custom-media',
+		Once: async root => {
+			const customMedia = Object.assign(
+				await customMediaPromise,
+				getCustomMediaFromRoot(root, { preserve })
+			);
 
-		await writeCustomMediaToExports(customMedia, exportTo);
+			await writeCustomMediaToExports(customMedia, exportTo);
 
-		transformAtrules(root, customMedia, { preserve });
-	};
-});
+			transformAtrules(root, customMedia, { preserve });
+		}
+	}
+};
+
+creator.postcss = true
+
+export default creator

lib/get-custom-media-from-imports.js

@@ -1,6 +1,6 @@
 import fs from 'fs';
 import path from 'path';
-import postcss from 'postcss';
+import { parse } from 'postcss';
 import getMediaAstFromMediaString from './media-ast-from-string';
 import getCustomMedia from './custom-media-from-root';
 
@@ -9,7 +9,7 @@ import getCustomMedia from './custom-media-from-root';
 
 async function getCustomMediaFromCSSFile(from) {
 	const css = await readFile(from);
-	const root = postcss.parse(css, { from });
+	const root = parse(css, { from });
 
 	return getCustomMedia(root, { preserve: true });
 }

package.json

@@ -24,26 +24,36 @@
     "test:tape": "postcss-tape"
   },
   "engines": {
-    "node": ">=6.0.0"
+    "node": ">=10.0.0"
   },
-  "dependencies": {
-    "postcss": "^7.0.14"
+  "peerDependencies": {
+    "postcss": "^8.1.0"
   },
   "devDependencies": {
-    "@babel/core": "^7.4.0",
-    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
-    "@babel/preset-env": "^7.4.2",
-    "babel-eslint": "^10.0.1",
-    "eslint": "^5.16.0",
-    "eslint-config-dev": "^2.0.0",
-    "postcss-tape": "^4.0.0",
+    "@babel/core": "^7.11.6",
+    "@babel/plugin-syntax-dynamic-import": "^7.8.3",
+    "@babel/preset-env": "^7.11.5",
+    "@rollup/plugin-babel": "^5.2.1",
+    "babel-eslint": "^10.1.0",
+    "eslint": "^7.10.0",
+    "postcss": "^8.1.0",
+    "postcss-tape": "^6.0.0",
     "pre-commit": "^1.2.2",
-    "rollup": "^1.7.4",
-    "rollup-plugin-babel": "^4.3.2"
+    "rollup": "^2.28.2"
   },
   "eslintConfig": {
-    "extends": "dev",
-    "parser": "babel-eslint"
+    "env": {
+      "browser": true,
+      "es6": true,
+      "node": true
+    },
+    "extends": "eslint:recommended",
+    "parser": "babel-eslint",
+    "parserOptions": {
+      "ecmaVersion": 2018,
+      "impliedStrict": true,
+      "sourceType": "module"
+    }
   },
   "keywords": [
     "postcss",