refactor: to esm

.eslintrc

@@ -1,6 +1,7 @@
 {
   "parserOptions": {
-    "ecmaVersion": 2020
+    "ecmaVersion": 2020,
+    "sourceType": "module"
   },
   "rules": {
     "indent": [2, 2, {"SwitchCase": 1}],

README.md

@@ -35,7 +35,7 @@ posthtml([ postcss(postcssPlugins, postcssOptions, filterType) ])
     .then((result) => console.log(result.html))
 ```
 
-If you don't pass arguments to `posthtml-postcss`, it will use your project's PostCSS configuration (see [`postcss-load-config`](https://www.npmjs.com/package/postcss-load-config)).
+If you don't pass any arguments to `posthtml-postcss`, it will try to use your project's PostCSS configuration (see [`postcss-load-config`](https://www.npmjs.com/package/postcss-load-config)).
 
 Notice that we're setting the option `from` when calling `process`. `posthtml-postcss` forwards this to PostCSS, which is useful for syntax error messages. (`postcss-cli` and `gulp-posthtml` are setting `from` automatically.)
 

lib/index.js

@@ -1,60 +1,64 @@
-const postcss = require('postcss');
-const postcssrc = require('postcss-load-config');
-
-module.exports = function (plugins, options, filterType) {
-  if (arguments.length === 0) {
-    const rc = postcssrc.sync();
-    plugins = rc.plugins;
-    options = rc.options;
+import postcss from 'postcss'
+import postcssConfig from 'postcss-load-config'
+
+const plugin = (plugins = null, options = null, filterType = null) => {
+  if (plugins === null && options === null && filterType === null) {
+    const rc = postcssConfig.sync()
+    plugins = rc.plugins
+    options = rc.options
   }
 
-  plugins = [].concat(plugins).filter(Boolean);
-  options = options || {};
+  plugins = [].concat(plugins).filter(Boolean)
+  options = options || {}
 
-  const css = postcss(plugins);
+  const css = postcss(plugins)
 
   return function (tree) {
-    const promises = [];
+    const promises = []
 
     tree.walk(node => {
-      let promise;
+      let promise
 
       if (node.tag === 'style' && node.content) {
-        let meetsFilter = true;
+        let meetsFilter = true
+
         if (filterType) {
-          const typeAttr = (node.attrs && node.attrs.type) ? node.attrs.type.trim() : '';
-          const meetsTypeAttr = filterType.test(typeAttr);
-          const meetsStandardType = filterType.test('text/css') && (meetsTypeAttr || typeAttr === '');
-          const meetsOtherType = !meetsStandardType && meetsTypeAttr;
-          meetsFilter = meetsStandardType || meetsOtherType;
+          const typeAttr = (node.attrs && node.attrs.type) ? node.attrs.type.trim() : ''
+          const meetsTypeAttr = filterType.test(typeAttr)
+          const meetsStandardType = filterType.test('text/css') && (meetsTypeAttr || typeAttr === '')
+          const meetsOtherType = !meetsStandardType && meetsTypeAttr
+          meetsFilter = meetsStandardType || meetsOtherType
         }
 
         if (meetsFilter) {
-          const styles = [].concat(node.content).join('');
-          const from = options.from || tree.options.from;
+          const styles = [].concat(node.content).join('')
+          const from = options.from || tree.options.from
+
           promise = css.process(styles, {...options, from})
             .then(result => {
-              node.content = [result.css];
-            });
+              node.content = [result.css]
+            })
 
-          promises.push(promise);
+          promises.push(promise)
         }
       }
 
       if (node.attrs && node.attrs.style) {
         promise = css.process(node.attrs.style, options)
           .then(result => {
-            node.attrs.style = result.css;
-          });
+            node.attrs.style = result.css
+          })
 
-        promises.push(promise);
+        promises.push(promise)
       }
 
-      return node;
-    });
+      return node
+    })
 
     return Promise.all(promises).then(() => {
-      return tree;
-    });
-  };
-};
+      return tree
+    })
+  }
+}
+
+export default plugin

package.json

@@ -7,9 +7,10 @@
   "author": "Ivan Voischev <voischev.ivan@ya.ru>",
   "bugs": "https://github.com/posthtml/posthtml-postcss/issues",
   "homepage": "https://github.com/posthtml/posthtml-postcss",
-  "main": "lib/index.js",
+  "type": "module",
+  "exports": "./lib/index.js",
   "engines": {
-    "node": ">=16"
+    "node": ">=18"
   },
   "scripts": {
     "dev": "vitest",

vitest.config.js

@@ -0,0 +1,7 @@
+import {defineConfig} from 'vitest/config'
+
+export default defineConfig({
+  test: {
+    include: ['**/*test.{js,ts}'],
+  },
+})