refactor: migrate on message api for export (#834)

Author: evilebottnawi

lib/loader.js

@@ -123,10 +123,13 @@ module.exports = function loader(content, map) {
         .warnings()
         .forEach((warning) => this.emitWarning(new Warning(warning)));
 
+      const messages = result.messages || [];
       const { camelCase, exportOnlyLocals, importLoaders } = options;
-      const { importItems, urlItems, exports } = parserOptions;
+      const { importItems, urlItems } = parserOptions;
+
       // Run other loader (`postcss-loader`, `sass-loader` and etc) for importing CSS
       const importUrlPrefix = getImportPrefix(this, importLoaders);
+
       // Prepare replacer to change from `___CSS_LOADER_IMPORT___INDEX___` to `require('./file.css').locals`
       const importItemReplacer = (item) => {
         const match = placholderRegExps.importItem.exec(item);
@@ -152,7 +155,7 @@ module.exports = function loader(content, map) {
         )}).locals[${JSON.stringify(importItem.export)}] + "`;
       };
 
-      let exportCode = compileExports(exports, camelCase, (valueAsString) =>
+      let exportCode = compileExports(messages, camelCase, (valueAsString) =>
         valueAsString.replace(placholderRegExps.importItemG, importItemReplacer)
       );
 

lib/plugins/postcss-icss-parser.js

@@ -8,9 +8,8 @@ const pluginName = 'postcss-icss-parser';
 module.exports = postcss.plugin(
   pluginName,
   (options) =>
-    function process(css) {
+    function process(css, result) {
       const importItems = options.importItems || [];
-      const urlItems = options.urlItems || [];
       const imports = {};
       const icss = icssUtils.extractICSS(css);
       const exports = icss.icssExports;
@@ -61,13 +60,18 @@ module.exports = postcss.plugin(
 
       // Replace tokens in export
       Object.keys(exports).forEach((exportName) => {
-        exports[exportName] = replaceImportsInString(exports[exportName]);
+        result.messages.push({
+          pluginName,
+          type: 'export',
+          item: {
+            key: exportName,
+            value: replaceImportsInString(exports[exportName]),
+          },
+        });
       });
 
       /* eslint-disable no-param-reassign */
       options.importItems = importItems;
-      options.urlItems = urlItems;
-      options.exports = exports;
       /* eslint-enable no-param-reassign */
     }
 );

lib/utils.js

@@ -37,19 +37,18 @@ function dashesCamelCase(str) {
   );
 }
 
-function compileExports(exports, camelCaseKeys, valueHandler) {
-  if (!exports || Object.keys(exports).length === 0) {
-    return '';
-  }
+function compileExports(messages, camelCaseKeys, valueHandler) {
+  const exports = messages
+    .filter((message) => message.type === 'export')
+    .reduce((accumulator, message) => {
+      const { key, value } = message.item;
 
-  const exportJs = Object.keys(exports)
-    .reduce((res, key) => {
-      let valueAsString = JSON.stringify(exports[key]);
+      let valueAsString = JSON.stringify(value);
 
       valueAsString = valueHandler(valueAsString);
 
       function addEntry(k) {
-        res.push(`\t${JSON.stringify(k)}: ${valueAsString}`);
+        accumulator.push(`\t${JSON.stringify(k)}: ${valueAsString}`);
       }
 
       let targetKey;
@@ -82,11 +81,10 @@ function compileExports(exports, camelCaseKeys, valueHandler) {
           break;
       }
 
-      return res;
-    }, [])
-    .join(',\n');
+      return accumulator;
+    }, []);
 
-  return `{\n${exportJs}\n}`;
+  return exports.length > 0 ? `{\n${exports.join(',\n')}\n}` : '';
 }
 
 function getLocalIdent(loaderContext, localIdentName, localName, options) {