Merge pull request #3 from sullenor/postcss-as-a-loader

Postcss as a loader

Author: mightyaleksey

index.js

@@ -1,78 +1,19 @@
 'use strict';
 
-if (global._cssModulesPolyfill) {
-  throw new Error('only one instance of css-modules/polyfill is allowed');
-}
-
-global._cssModulesPolyfill = true;
-
-var assign = require('object-assign');
-var options = {};
+var path = require('path');
 
-/**
- * Posibility to pass custom options to the module
- * @param {object} opts
- */
-module.exports = function (opts) {
-  assign(options, opts);
+var escape = function (str) {
+    return str.replace(/[\[\]\/{}()*+?.\\^$|-]/g, '\\$&');
 };
 
-var Core = require('css-modules-loader-core');
-var pluginsCache;
-
-/**
- * Caching plugins for the future calls
- * @return {array}
- */
-function loadPlugins() {
-  // retrieving from cache if they are already loaded
-  if (pluginsCache) {
-    return pluginsCache;
-  }
-
-  // PostCSS plugins passed to FileSystemLoader
-  var plugins = options.use || options.u;
-  if (!plugins) {
-    plugins = Core.defaultPlugins;
-  } else {
-    if (typeof plugins === 'string') {
-      plugins = [ plugins ];
-    }
-
-    plugins = plugins.map(function requirePlugin (name) {
-      // assume functions are already required plugins
-      if (typeof name === 'function') {
-        return name;
-      }
-
-      var plugin = require(require.resolve(name));
+var regexp = ['src', 'test'].map(function (i) {
+    return '^' + escape(path.join(__dirname, i) + path.sep);
+}).join('|');
 
-      // custom scoped name generation
-      if (name === 'postcss-modules-scope') {
-        options[name] = options[name] || {};
-        options[name].generateScopedName = createScopedNameFunc(plugin);
-      }
+require('babel/register')({
+    only:   new RegExp('(' + regexp + ')'),
+    ignore: false,
+    loose: 'all'
+});
 
-      if (name in options) {
-        plugin = plugin(options[name]);
-      } else {
-        plugin = plugin.postcss || plugin();
-      }
-
-      return plugin;
-    });
-  }
-
-  return pluginsCache = plugins;
-}
-
-var FileSystemLoader = require('css-modules-loader-core/lib/file-system-loader');
-var path = require('path');
-
-require.extensions['.css'] = function (m, filename) {
-  var plugins = loadPlugins();
-  var loader = new FileSystemLoader(path.dirname(filename), plugins);
-  var tokens = loader.fetchSync(path.basename(filename), '/');
-
-  return m._compile('module.exports = ' + JSON.stringify(tokens), filename);
-};
+module.exports = require('./src');

package.json

@@ -4,18 +4,18 @@
   "description": "A require hook to compile CSS Modules on the fly",
   "main": "index.js",
   "dependencies": {
-    "babel": "^5.6.14",
-    "object-assign": "^3.0.0"
+    "babel": "^5.8.20",
+    "css-modules-loader-core": "0.0.11",
+    "postcss": "^4.1.16",
+    "postcss-modules-extract-imports": "0.0.5",
+    "postcss-modules-local-by-default": "0.0.9",
+    "postcss-modules-scope": "0.0.8"
   },
   "devDependencies": {
     "mocha": "^2.2.5"
   },
   "scripts": {
-    "clone": "git clone https://github.com/sullenor/css-modules-loader-core.git node_modules/css-modules-loader-core",
-    "deps": "cd node_modules/css-modules-loader-core && npm i",
-    "postinstall": "npm run clone && npm run deps",
-    "preinstall": "rm -rf node_modules/css-modules-loader-core",
-    "test": "mocha test"
+    "test": "mocha --compilers js:babel/register"
   },
   "repository": {
     "type": "git",

src/guard.js

@@ -0,0 +1,7 @@
+'use strict';
+
+if (global._cssModulesPolyfill) {
+  throw new Error('only one instance of css-modules/polyfill is allowed');
+}
+
+global._cssModulesPolyfill = true;

src/hook.js

@@ -0,0 +1,11 @@
+'use strict';
+
+/**
+ * @param {function} compile
+ */
+module.exports = function (compile) {
+  require.extensions['.css'] = function (m, filename) {
+    var tokens = compile(filename);
+    return m._compile('module.exports = ' + JSON.stringify(tokens), filename);
+  };
+};

src/index.js

@@ -0,0 +1,68 @@
+'use strict';
+
+import './guard';
+import hook from './hook';
+import postcss from 'postcss';
+import { basename, dirname, join, resolve } from 'path';
+import { readFileSync } from 'fs';
+
+import extractImports from 'postcss-modules-extract-imports';
+import localByDefault from 'postcss-modules-local-by-default';
+import scope from 'postcss-modules-scope';
+import parser from './parser';
+
+let plugins = [localByDefault, extractImports, scope];
+
+const load = (sourceString, sourcePath, trace, pathFetcher) => {
+  let exportTokens = {};
+  let result = postcss(plugins.concat(new parser({ exportTokens, pathFetcher, trace })))
+    .process(sourceString, {from: '/' + sourcePath})
+    .stringify();
+
+  return { injectableSource: result.css, exportTokens: exportTokens };
+}
+
+hook(filename => {
+  const root = dirname(filename);
+  const sources = {};
+  const tokensByFile = {};
+  let importNr = 0;
+
+  const fetch = (_newPath, _relativeTo, _trace) => {
+    let newPath = _newPath.replace(/^["']|["']$/g, '');
+    let trace = _trace || String.fromCharCode(importNr++);
+
+    let relativeDir = dirname(_relativeTo);
+    let rootRelativePath = resolve(relativeDir, newPath);
+    let fileRelativePath = resolve(join(root, relativeDir), newPath);
+
+    const tokens = tokensByFile[fileRelativePath];
+    if (tokens) {
+      return tokens;
+    }
+
+    let source = readFileSync(fileRelativePath, 'utf-8');
+    let { injectableSource, exportTokens } = load(source, rootRelativePath, trace, fetch);
+
+    sources[trace] = injectableSource;
+    tokensByFile[fileRelativePath] = exportTokens;
+
+    return exportTokens;
+  }
+
+  return fetch(basename(filename), '/');
+});
+
+/**
+ * @param  {object} opts
+ * @param  {array}  opts.u
+ * @param  {array}  opts.use
+ */
+export default function configure(opts) {
+  opts = opts || {};
+
+  let customPlugins = opts.u || opts.use;
+  plugins = Array.isArray(customPlugins)
+    ? customPlugins
+    : [localByDefault, extractImports, scope];
+}

src/parser.js

@@ -0,0 +1,66 @@
+'use strict';
+
+import { plugin } from 'postcss';
+
+const importRegexp = /^:import\((.+)\)$/
+
+export default plugin('parser', function (opts) {
+  opts = opts || {};
+
+  let exportTokens = opts.exportTokens;
+  let translations = {};
+
+  const fetchImport = (importNode, relativeTo, depNr) => {
+    let file = importNode.selector.match( importRegexp )[1];
+    let depTrace = opts.trace + String.fromCharCode(depNr);
+    let exports = opts.pathFetcher(file, relativeTo, depTrace);
+
+    importNode.each(decl => {
+      if (decl.type === 'decl') {
+        translations[decl.prop] = exports[decl.value];
+      }
+    });
+
+    importNode.removeSelf();
+  }
+
+  const fetchAllImports = css => {
+    let imports = 0;
+
+    css.each(node => {
+      if (node.type === 'rule' && node.selector.match(importRegexp)) {
+        fetchImport(node, css.source.input.from, imports++);
+      }
+    });
+  }
+
+  const linkImportedSymbols = css => css.eachDecl(decl => {
+    Object.keys(translations).forEach(translation => {
+      decl.value = decl.value.replace(translation, translations[translation])
+    });
+  });
+
+  const handleExport = exportNode => {
+    exportNode.each(decl => {
+      if (decl.type === 'decl') {
+        Object.keys(translations).forEach(translation => {
+          decl.value = decl.value.replace(translation, translations[translation])
+        });
+
+        exportTokens[decl.prop] = decl.value;
+      }
+    });
+
+    exportNode.removeSelf();
+  }
+
+  const extractExports = css => css.each(node => {
+    if (node.type === 'rule' && node.selector === ':export') handleExport(node);
+  });
+
+  return css => {
+    fetchAllImports(css);
+    linkImportedSymbols(css);
+    extractExports(css);
+  }
+});

test/cssi/interchange-format/colors.css

@@ -0,0 +1,7 @@
+:export {
+  blackShadow: x__single_import_export_colors__blackShadow;
+}
+
+.x__single_import_export_colors__blackShadow {
+  box-shadow: 0 0 10px -2px black;
+}

test/cssi/interchange-format/expected.css

@@ -0,0 +1,6 @@
+.x__single_import_export_colors__blackShadow {
+  box-shadow: 0 0 10px -2px black;
+}
+.x__single_import_export_source__localName {
+  color: red;
+}

test/cssi/interchange-format/expected.json

@@ -0,0 +1,3 @@
+{
+  "localName": "x__single_import_export_source__localName x__single_import_export_colors__blackShadow"
+}

test/cssi/interchange-format/source.css

@@ -0,0 +1,11 @@
+:import("./colors.css") {
+  i__tmp_import_djhgdsag: blackShadow;
+}
+
+:export {
+  localName: x__single_import_export_source__localName i__tmp_import_djhgdsag;
+}
+
+.x__single_import_export_source__localName {
+  color: red;
+}