add support for file extensions beyond .css

README.md

@@ -42,7 +42,7 @@ console.log(styles.someClass); // prints Test__someClass___2Frqu
 npm install --save-dev babel-plugin-css-modules-transform
 ```
 
-**Include plugin to `.babelrc`**
+**Include plugin in `.babelrc`**
 
 ```json
 {
@@ -57,14 +57,15 @@ npm install --save-dev babel-plugin-css-modules-transform
 {
     "plugins": [
         [
-            "css-modules-transform", { 
+            "css-modules-transform", {
                 "generateScopedName": "[name]__[local]___[hash:base64:5]", // in case you don't want to use a function
                 "generateScopedName": "./path/to/module-exporting-a-function.js", // in case you want to use a function
                 "generateScopedName": "npm-module-name",
                 "preprocessCss": "./path/to/module-exporting-a-function.js",
                 "preprocessCss": "npm-module-name",
                 "processCss": "./path/to/module-exporting-a-function.js",
                 "processCss": "npm-module-name",
+                "extensions": [".css", ".scss", ".less"], // list extensions to process; defaults to .css
                 "append": [
                     "npm-module-name",
                     "./path/to/module-exporting-a-function.js"
@@ -79,6 +80,42 @@ npm install --save-dev babel-plugin-css-modules-transform
 }
 ```
 
+## Using a preprocessor
+
+When using this plugin with a preprocessor, you'll need to configure it as such:
+
+
+```
+// ./path/to/module-exporting-a-function.js
+var sass = require('node-sass');
+var path = require('path');
+
+module.exports = function processSass(data, filename) {
+    var result;
+    result = sass.renderSync({
+        data: data,
+        file: filename
+    }).css;
+    return result.toString('utf8');
+};
+```
+
+and then add any relevant extensions to your plugin config:
+
+```
+{
+    "plugins": [
+        [
+            "css-modules-transform", {
+                "preprocessCss": "./path/to/module-exporting-a-function.js",
+                "extensions": [".css", ".scss"]
+            }
+        ]
+    ]
+}
+
+```
+
 ## License
 
 MIT

src/index.js

@@ -31,13 +31,25 @@ export default function transformCssModules({ types: t }) {
      * @returns {Array} array of class names
      */
     function requireCssFile(filepath, cssFile) {
-        const from = resolveModulePath(filepath);
-        return require(resolve(from, cssFile));
+        let filePathOrModuleName = cssFile;
+
+        // only resolve path to file when we have a file path
+        if (!/^\w/i.test(filePathOrModuleName)) {
+            const from = resolveModulePath(filepath);
+            filePathOrModuleName = resolve(from, filePathOrModuleName);
+        }
+        return require(filePathOrModuleName);
     }
 
     // is css modules require hook initialized?
     let initialized = false;
 
+    let matchExtensions = /\.css/i;
+    function matcher(extensions = ['.css']) {
+        const extensionsPatern = extensions.join('|').replace('.', '\.');
+        return new RegExp(`(${extensionsPatern})`, 'i');
+    }
+
     return {
         visitor: {
             Program(path, { opts }) {
@@ -47,6 +59,10 @@ export default function transformCssModules({ types: t }) {
 
                 const currentConfig = { ...defaultOptions, ...opts };
 
+                // match file extensions, speeds up transform by creating one
+                // RegExp ahead of execution time
+                matchExtensions = matcher(currentConfig.extensions);
+
                 // check if there are simple requires and if they are functions
                 simpleRequires.forEach(key => {
                     if (typeof currentConfig[key] !== 'string') {
@@ -133,17 +149,18 @@ export default function transformCssModules({ types: t }) {
                     return;
                 }
 
-                if (/\.css/i.test(args[0].value)) {
-                    const [ { value: cssPath }] = args;
+                const [{ value: stylesheetPath }] = args;
 
+                if (matchExtensions.test(stylesheetPath)) {
                     // if parent expression is variable declarator, replace right side with tokens
                     if (!t.isVariableDeclarator(path.parent)) {
                         throw new Error(
-                            `You can't import css file ${cssPath} to a module scope.`
+                            `You can't import css file ${stylesheetPath} to a module scope.`
                         );
                     }
 
-                    const tokens = requireCssFile(file.opts.filename, args[0].value);
+                    const requiringFile = file.opts.filename;
+                    const tokens = requireCssFile(requiringFile, stylesheetPath);
 
                     /* eslint-disable new-cap */
                     path.replaceWith(t.ObjectExpression(

test/extensions.scss

@@ -0,0 +1,4 @@
+.sassy {
+    display: block;
+    color: pink;
+}

test/fixtures/extensions.expected.js

@@ -0,0 +1,8 @@
+'use strict';
+
+var css = {
+  'className': 'styles__className___385m0 parent__block___33Sxl'
+};
+var scss = {
+  'sassy': 'extensions__sassy___12Yag'
+};

test/fixtures/extensions.js

@@ -0,0 +1,2 @@
+var css = require('../styles.css');
+var scss = require('../extensions.scss');

test/index.spec.js

@@ -136,4 +136,8 @@ describe('babel-plugin-css-modules-transform', () => {
 
         stream.end();
     });
+
+    it('should accept file extensions as an array', () => {
+        expect(transform('fixtures/extensions.js', {extensions: ['.scss', '.css']}).code).to.be.equal(readExpected('fixtures/extensions.expected.js'));
+    });
 });