🐎 🐛 optimize plugin to initalize options only once

Also fixes problems with circular dependencies when used with babel-node and babel-register, #35

Also this provides functionality to use watch mode, only thing a developer has to do is to enable devMode, #33

README.md

@@ -175,33 +175,6 @@ To extract all files in a single directory, give an object:
 Note that `relativeRoot` is used to resolve relative directory names, available
 as `[path]` in `filename` pattern.
 
-## Using a `babel-register`
-
-Make sure you set `ignore` option of `babel-register` to ignore all files used by css-modules-require-hook to process your css files.
-
-**Require `babel-register` only once otherwise it will fail**
-**Be aware, you need to explicitly ignore `node_modules` if you set `ignore` option**
-
-```js
-require('babel-register')({
-    ignore: /(processCss\.js|node_modules)/ // regex matching all files used by css-modules-require-hook to process your css files
-})
-```
-
-## Using in mocha
-
-Create a js file with content
-
-**Be aware, you need to explicitly ignore `node_modules` if you set `ignore` option**
-
-```js
-require('babel-register')({
-    ignore: /(processCss\.js|node_modules)/ // regex matching all files used by css-modules-require-hook to process your css files
-})
-```
-
-and then set this file as a compiler `--compilers js:<name-of-your-file>.js`
-
 ## Alternatives
 
 - [babel-plugin-transform-postcss](https://github.com/wbyoung/babel-plugin-transform-postcss) - which supports async plugins and does not depend on `css-modules-require-hook`.

src/index.js

@@ -43,6 +43,10 @@ export default function transformCssModules({ types: t }) {
 
     // is css modules require hook initialized?
     let initialized = false;
+    // are we requiring a module for preprocessCss, processCss, etc?
+    // we don't want them to be transformed using this plugin
+    // because it will cause circular dependency in babel-node and babel-register process
+    let inProcessingFunction = false;
 
     let matchExtensions = /\.css$/i;
 
@@ -63,61 +67,80 @@ export default function transformCssModules({ types: t }) {
         );
     }
 
-    return {
-        visitor: {
-            Program(path, state) {
-                if (initialized) {
-                    return;
-                }
-
-                const currentConfig = { ...defaultOptions, ...state.opts };
-                // this is not a css-require-ook config
-                delete currentConfig.extractCss;
-
-                // match file extensions, speeds up transform by creating one
-                // RegExp ahead of execution time
-                matchExtensions = matcher(currentConfig.extensions);
+    const cssMap = new Map();
+    let thisPluginOptions = null;
 
-                // Add a space in current state for css filenames
-                state.$$css = {
-                    styles: new Map()
-                };
-
-                const pushStylesCreator = (toWrap) => (css, filepath) => {
-                    let processed;
+    const pluginApi = {
+        manipulateOptions(options) {
+            if (initialized || inProcessingFunction) {
+                return options;
+            }
 
-                    if (typeof toWrap === 'function') {
-                        processed = toWrap(css, filepath);
-                    }
+            // find options for this plugin
+            // we have to use this hack because plugin.key does not have to be 'css-modules-transform'
+            // so we will identify it by comparing manipulateOptions
+            thisPluginOptions = options.plugins.filter(
+              ([plugin]) => plugin.manipulateOptions === pluginApi.manipulateOptions
+            )[0][1];
 
-                    if (typeof processed !== 'string') processed = css;
+            const currentConfig = { ...defaultOptions, ...thisPluginOptions };
+            // this is not a css-require-ook config
+            delete currentConfig.extractCss;
 
-                    if (!state.$$css.styles.has(filepath)) {
-                        state.$$css.styles.set(filepath, processed);
-                        extractCssFile(process.cwd(), filepath, processed, state);
-                    }
+            // match file extensions, speeds up transform by creating one
+            // RegExp ahead of execution time
+            matchExtensions = matcher(currentConfig.extensions);
 
-                    return processed;
-                };
+            const pushStylesCreator = (toWrap) => (css, filepath) => {
+                let processed;
 
-                // resolve options
-                Object.keys(requireHooksOptions).forEach(key => {
-                    // skip undefined options
-                    if (currentConfig[key] === undefined) {
-                        return;
-                    }
+                if (typeof toWrap === 'function') {
+                    processed = toWrap(css, filepath);
+                }
 
-                    currentConfig[key] = requireHooksOptions[key](currentConfig[key], currentConfig);
-                });
+                if (typeof processed !== 'string') processed = css;
 
-                // wrap or define processCss function that collect generated css
-                currentConfig.processCss = pushStylesCreator(currentConfig.processCss);
+                // set css content only if is new
+                if (!cssMap.has(filepath) || cssMap.get(filepath) !== processed) {
+                    cssMap.set(filepath, processed);
+                }
 
-                require('css-modules-require-hook')(currentConfig);
+                return processed;
+            };
 
-                initialized = true;
-            },
+            // resolve options
+            Object.keys(requireHooksOptions).forEach(key => {
+                // skip undefined options
+                if (currentConfig[key] === undefined) {
+                    return;
+                }
 
+                inProcessingFunction = true;
+                currentConfig[key] = requireHooksOptions[key](currentConfig[key], currentConfig);
+                inProcessingFunction = false;
+            });
+
+            // wrap or define processCss function that collect generated css
+            currentConfig.processCss = pushStylesCreator(currentConfig.processCss);
+
+            require('css-modules-require-hook')(currentConfig);
+
+            initialized = true;
+
+            return options;
+        },
+        post() {
+            // extract css only if is this option set
+            if (thisPluginOptions.extractCss) {
+                // always rewrite file :-/
+                extractCssFile(
+                    process.cwd(),
+                    cssMap,
+                    thisPluginOptions.extractCss
+                );
+            }
+        },
+        visitor: {
             // import styles from './style.css';
             ImportDefaultSpecifier(path, { file }) {
                 const { value } = path.parentPath.node.source;
@@ -162,4 +185,6 @@ export default function transformCssModules({ types: t }) {
             }
         }
     };
+
+    return pluginApi;
 }

src/utils/extractCssFile.js

@@ -7,18 +7,11 @@ export const PATH_VARIABLES = ['[path]', '[name]'];
  * Extracts CSS to file
  *
  * @param {String} cwd
- * @param {String} filepath
- * @param {String} css
- * @param {Object} state
+ * @param {Map} cssMap
+ * @param {String|Object} extractCss
  * @returns {null}
  */
-export default function extractCssFile(cwd, filepath, css, state) {
-    const { extractCss = null } = state.opts;
-
-    if (!extractCss) {
-        return null;
-    }
-
+export default function extractCssFile(cwd, cssMap, extractCss) {
     // this is the case where a single extractCss is requested
     if (typeof(extractCss) === 'string') {
         // check if extractCss contains some from pattern variables, if yes throw!
@@ -28,15 +21,9 @@ export default function extractCssFile(cwd, filepath, css, state) {
             }
         });
 
-        // If this is the first file, then we should replace
-        // old content
-        if (state.$$css.styles.size === 1) {
-            return writeCssFile(extractCss, css);
-        }
+        const css = Array.from(cssMap.values()).join('');
 
-        // this should output in a single file.
-        // Let's append the new file content.
-        return writeCssFile(extractCss, css, true);
+        return writeCssFile(extractCss, css);
     }
 
     // This is the case where each css file is written in
@@ -52,18 +39,20 @@ export default function extractCssFile(cwd, filepath, css, state) {
         throw new Error('[name] variable has to be used in extractCss.filename option');
     }
 
-    // Make css file name relative to relativeRoot
-    const relativePath = relative(
-        resolve(cwd, relativeRoot),
-        filepath
-    );
-
-    const destination = join(
-        resolve(cwd, dir),
-        filename
-    )
-        .replace(/\[name]/, basename(filepath, extname(filepath)))
-        .replace(/\[path]/, dirname(relativePath));
-
-    writeCssFile(destination, css);
+    cssMap.forEach((css, filepath) => {
+        // Make css file name relative to relativeRoot
+        const relativePath = relative(
+            resolve(cwd, relativeRoot),
+            filepath
+        );
+
+        const destination = join(
+            resolve(cwd, dir),
+            filename
+        )
+            .replace(/\[name]/, basename(filepath, extname(filepath)))
+            .replace(/\[path]/, dirname(relativePath));
+
+        writeCssFile(destination, css);
+    });
 }