feat: upgrade to PostCSS 8

.rollup.js

@@ -2,7 +2,7 @@ import pkg from './package.json'
 
 export default {
 	...pkg.rollup,
-	plugins: pkg.rollup.plugins.map(plugin => require(plugin)()),
+	plugins: pkg.rollup.plugins.map(plugin => require(plugin).default()),
 	onwarn(warning, warn) {
 		if (warning.code !== 'UNRESOLVED_IMPORT') warn(warning)
 	}

README.md

@@ -35,7 +35,7 @@
 Add [PostCSS Environment Variables] to your project:
 
 ```bash
-npm install postcss-env-function --save-dev
+npm install postcss postcss-env-function --save-dev
 ```
 
 Use [PostCSS Environment Variables] to process your CSS:

package.json

@@ -17,27 +17,30 @@
     "build:watch": "npx rollup -c .rollup.js --watch",
     "lint": "npx eslint --cache src",
     "lint:fix": "npx eslint --cache --fix",
-    "pretest": "npm install && npm run build",
+    "pretest": "npm run build",
     "test": "npm run lint && npm run tape",
-    "tape": "npx postcss-tape",
+    "tape": "postcss-tape",
     "prepublishOnly": "npm test"
   },
   "engines": {
-    "node": ">=8.0.0"
+    "node": ">=10.0.0"
   },
   "dependencies": {
-    "postcss": "^7.0.27",
-    "postcss-values-parser": "^3.2.0"
+    "postcss-values-parser": "^5.0.0"
+  },
+  "peerDependencies": {
+    "postcss": "^8.0.0"
   },
   "devDependencies": {
-    "@babel/core": "^7.9.0",
-    "@babel/preset-env": "^7.9.5",
-    "babel-eslint": "^10.1.0",
-    "eslint": "^6.8.0",
-    "postcss-tape": "^5.0.2",
+    "@babel/core": "^7.13.10",
+    "@babel/preset-env": "^7.13.10",
+    "@babel/eslint-parser": "^7.13.10",
+    "eslint": "^7.22.0",
+    "postcss": "^8.2.8",
+    "postcss-tape": "^6.0.0",
     "pre-commit": "^1.2.2",
-    "rollup": "^2.7.2",
-    "rollup-plugin-babel": "^4.4.0"
+    "rollup": "^2.41.2",
+    "@rollup/plugin-babel": "^5.3.0"
   },
   "babel": {
     "presets": [
@@ -55,12 +58,12 @@
       "node": true
     },
     "extends": "eslint:recommended",
-    "parser": "babel-eslint"
+    "parser": "@babel/eslint-parser"
   },
   "rollup": {
     "input": "src/index.js",
     "plugins": [
-      "rollup-plugin-babel"
+      "@rollup/plugin-babel"
     ],
     "output": [
       {

src/index.js

@@ -1,29 +1,34 @@
-import postcss from 'postcss';
 import getReplacedValue from './lib/get-replaced-value';
-import getSupportedValue from './lib/get-supported-value';
-import setSupportedValue from './lib/set-supported-value';
 import importEnvironmentVariablesFromSources from './lib/import-from';
 
-export default postcss.plugin('postcss-env-fn', opts => {
+/**
+ * @param {{importFrom?: string[]}} opts
+ * @returns {import('postcss').Plugin}
+ */
+module.exports = function creator(opts) {
 	// sources to import environment variables from
 	const importFrom = [].concat(Object(opts).importFrom || []);
 
 	// promise any environment variables are imported
 	const environmentVariablesPromise = importEnvironmentVariablesFromSources(importFrom);
 
-	return async root => {
-		const environmentVariables = await environmentVariablesPromise;
+	return {
+		postcssPlugin: 'postcss-env-fn',
+		async AtRule(atRule) {
+			const replacedValue = getReplacedValue(atRule.params, await environmentVariablesPromise);
 
-		root.walk(node => {
-			const supportedValue = getSupportedValue(node);
-
-			if (supportedValue) {
-				const replacedValue = getReplacedValue(supportedValue, environmentVariables);
+			if (replacedValue !== atRule.params) {
+				atRule.params = replacedValue;
+			}
+		},
+		async Declaration(decl) {
+			const replacedValue = getReplacedValue(decl.value, await environmentVariablesPromise);
 
-				if (replacedValue !== supportedValue) {
-					setSupportedValue(node, replacedValue);
-				}
+			if (replacedValue !== decl.value) {
+				decl.value = replacedValue;
 			}
-		});
+		}
 	};
-});
+};
+
+module.exports.postcss = true;

src/lib/get-replaced-value.js

@@ -2,7 +2,11 @@ import { parse } from 'postcss-values-parser';
 import updateEnvValue from './update-env-value';
 import walkEnvFuncs from './walk-env-funcs';
 
-// returns a value replaced with environment variables
+/**
+ * @param {string} originalValue
+ * @param variables
+ * @returns {string} returns a value replaced with environment variables
+ */
 export default (originalValue, variables) => {
 	// get the ast of the original value
 	const ast = parse(originalValue);

src/lib/import-from.js

@@ -2,9 +2,11 @@ import fs from 'fs';
 import path from 'path';
 import { parse } from 'postcss-values-parser';
 
-/* Import Custom Properties from Object
-/* ========================================================================== */
-
+/**
+ * Import Custom Properties from Object
+ * @param {{environmentVariables: Record<string, string>, 'environment-variables': Record<string, string>}} object
+ * @returns {Record<string, import('postcss-values-parser').Root>}
+ */
 function importEnvironmentVariablesFromObject(object) {
 	const environmentVariables = Object.assign(
 		{},
@@ -18,27 +20,33 @@ function importEnvironmentVariablesFromObject(object) {
 	return environmentVariables;
 }
 
-/* Import Custom Properties from JSON file
-/* ========================================================================== */
-
+/**
+ * Import Custom Properties from JSON file
+ * @param {string} from
+ * @returns {Promise<Record<string, import('postcss-values-parser').Root>>}
+ */
 async function importEnvironmentVariablesFromJSONFile(from) {
 	const object = await readJSON(path.resolve(from));
 
 	return importEnvironmentVariablesFromObject(object);
 }
 
-/* Import Custom Properties from JS file
-/* ========================================================================== */
-
+/**
+ * Import Custom Properties from JS file
+ * @param {string} from
+ * @returns {Promise<Record<string, import('postcss-values-parser').Root>>}
+ */
 async function importEnvironmentVariablesFromJSFile(from) {
 	const object = await import(path.resolve(from));
 
 	return importEnvironmentVariablesFromObject(object);
 }
 
-/* Import Custom Properties from Sources
-/* ========================================================================== */
-
+/**
+ * Import Custom Properties from Sources
+ * @param {(string|Function|Promise|{type:string,environmentVariables: Record<string, string>, 'environment-variables': Record<string, string>})[]} sources
+ * @returns {Promise<Record<string, import('postcss-values-parser').Root>>}
+ */
 export default function importEnvironmentVariablesFromSources(sources) {
 	return sources.map(source => {
 		if (source instanceof Promise) {
@@ -80,6 +88,10 @@ export default function importEnvironmentVariablesFromSources(sources) {
 /* Helper utilities
 /* ========================================================================== */
 
+/**
+ * @param {string} from
+ * @returns {Promise<string>}
+ */
 const readFile = from => new Promise((resolve, reject) => {
 	fs.readFile(from, 'utf8', (error, result) => {
 		if (error) {