Support css-loader 4

Closes #16

Author: c0gnize

README.md

@@ -1,5 +1,5 @@
 # dts-css-modules-loader
-Replacement for the [typings-for-css-modules-loader](https://github.com/Jimdo/typings-for-css-modules-loader). This loader does not make any changes in content of styles, just creates `*.d.ts` file during the work. It is assumed that the content will be preprocessed first by [css-loader](https://github.com/webpack-contrib/css-loader). Currently supported versions 2 and 3 of the `css-loader`.
+Replacement for the [typings-for-css-modules-loader](https://github.com/Jimdo/typings-for-css-modules-loader). This loader does not make any changes in content of styles, just creates `*.d.ts` file during the work. It is assumed that the content will be preprocessed first by [css-loader](https://github.com/webpack-contrib/css-loader). Currently supported versions 2, 3 and 4 of the `css-loader`.
 
 ## Installation
 ```bash
@@ -13,6 +13,7 @@ yarn add -D dts-css-modules-loader
 {
   test: /\.scss$/,
   use: [
+    'style-loader',
     {
       loader: 'dts-css-modules-loader',
       options: {
@@ -23,18 +24,17 @@ yarn add -D dts-css-modules-loader
     {
       loader: 'css-loader',
       options: {
-        modules: { // this option must be enabled
+        // options for the v4 of css-loader
+        modules: {
+          exportLocalsConvention: 'camelCaseOnly',
           localIdentName: '[local]'
         }
-        localsConvention: 'camelCaseOnly',
-        onlyLocals: true
       }
     },
     'sass-loader'
   ]
 }
 ```
-`css-loader` options presented for the third version.
 
 ## Options
 ### `namedExport`
@@ -54,7 +54,7 @@ export interface I_buttonScss {
   'buttonActive': string
 }
 declare const styles: I_buttonScss;
-export default styles;
+export = styles;
 ```
 
 ### `banner`

index.js

@@ -18,7 +18,6 @@ module.exports = function(content) {
 
   {
     const classes = getClasses(content);
-
     if (options.namedExport) {
       for (let c of classes) {
         typings += `export const ${c}: string;\n`;
@@ -29,7 +28,7 @@ module.exports = function(content) {
       for (let c of classes) {
         typings += `  '${c}': string;\n`;
       }
-      typings += `}\ndeclare const styles: ${i};\nexport default styles;\n`;
+      typings += `}\ndeclare const styles: ${i};\nexport = styles;\n`;
     }
   }
 
@@ -48,18 +47,31 @@ function getClasses(content) {
 
   /** @type {string[]} */
   let classes = [];
+  let isCssLoader4NamedExport = false;
 
-  // when `onlyLocals` is on
-  let from = content.indexOf('module.exports = {');
-  // when `onlyLocals` is off
-  from = ~from ? from : content.indexOf('exports.locals = {');
+  // check v4
+  let from = content.indexOf('___CSS_LOADER_EXPORT___.locals = {');
+  if (from === -1) {
+    from = content.indexOf('export const ');
+    isCssLoader4NamedExport = from !== -1;
+  }
+  // check v3
+  if (from === -1) {
+    // when `onlyLocals` is on
+    from = content.indexOf('module.exports = {');
+  }
+  if (from === -1) {
+    // when `onlyLocals` is off
+    from = content.indexOf('exports.locals = {');
+  }
 
   if (~from) {
     content = content.substr(from);
 
     /** @type {RegExpExecArray} */
     let match;
-    while (match = classesRegex.exec(content)) {
+    const regex = isCssLoader4NamedExport ? classesOfNamedExportRegex : classesRegex;
+    while (match = regex.exec(content)) {
       if (classes.indexOf(match[1]) === -1) {
         classes.push(match[1]);
       }
@@ -70,6 +82,7 @@ function getClasses(content) {
 }
 
 const classesRegex = /"([^"\\/;()\n]+)":/g;
+const classesOfNamedExportRegex = /export const (\w+) =/g;
 
 /**
  * @param {string} [path]

package.json

@@ -1,12 +1,12 @@
 {
   "name": "dts-css-modules-loader",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "description": "webpack loader to generate typings for css modules",
   "dependencies": {
-    "loader-utils": "^1.2.0"
+    "loader-utils": "^2.0.0"
   },
   "peerDependencies": {
-    "css-loader": "^2.0.0 || ^3.0.0"
+    "css-loader": "^2.0.0 || ^3.0.0 || ^4.0.0"
   },
   "keywords": [
     "css-modules",