refactor: code

Author: alexander-akait

README.md

@@ -407,6 +407,7 @@ module.exports = {
 - **[`publicPath`](#publicPath)**
 - **[`emit`](#emit)**
 - **[`esModule`](#esModule)**
+- **[`defaultExport`](#defaultExport)**
 
 #### `publicPath`
 
@@ -549,6 +550,60 @@ module.exports = {
 };
 ```
 
+#### `defaultExport`
+
+Type:
+
+```ts
+type defaultExport = boolean;
+```
+
+Default: `false`
+
+> **Note**
+>
+> This options will work only when you set `namedExport` to `true` in `css-loader`
+
+By default, `mini-css-extract-plugin` generates JS modules based on the `esModule` and `namedExport` options in `css-loader`.
+Using the `esModule` and `namedExport` options will allow you to better optimize your code.
+If you set `esModule: true` and `namedExport: true` for `css-loader` `mini-css-extract-plugin` will generate **only** a named export.
+Our official recommendation is to use only named export for better future compatibility.
+But for some applications, it is not easy to quickly rewrite the code from the default export to a named export.
+
+In case you need both default and named exports, you can enable this option:
+
+**webpack.config.js**
+
+```js
+const MiniCssExtractPlugin = require("mini-css-extract-plugin");
+
+module.exports = {
+  plugins: [new MiniCssExtractPlugin()],
+  module: {
+    rules: [
+      {
+        test: /\.css$/i,
+        use: [
+          {
+            loader: MiniCssExtractPlugin.loader,
+            options: {
+              defaultExport: true,
+            },
+          },
+          {
+            loader: "css-loader",
+            esModule: true,
+            modules: {
+              namedExport: true,
+            },
+          },
+        ],
+      },
+    ],
+  },
+};
+```
+
 ## Examples
 
 ### Recommended

src/index.js

@@ -37,6 +37,7 @@ const {
  * @property {boolean} [emit]
  * @property {boolean} [esModule]
  * @property {string} [layer]
+ * @property {boolean} [defaultExport]
  */
 
 /**

src/loader-options.json

@@ -27,6 +27,11 @@
     },
     "layer": {
       "type": "string"
+    },
+    "defaultExport": {
+      "type": "boolean",
+      "description": "Duplicate the named export with CSS modules locals to the default export (only when `esModules: true` for css-loader).",
+      "link": "https://github.com/webpack-contrib/mini-css-extract-plugin#defaultexports"
     }
   }
 }

src/loader.js

@@ -271,10 +271,17 @@ function pitch(request) {
           const exportsString = `export { ${identifiers
             .map(([id, key]) => `${id} as ${JSON.stringify(key)}`)
             .join(", ")} }`;
-          const exportDefaultString = `export default { ${identifiers
-            .map(([id, key]) => `${JSON.stringify(key)}: ${id}`)
-            .join(", ")} }`;
-          return `${localsString}\n${exportsString}\n${exportDefaultString}\n`;
+
+          const defaultExport =
+            typeof options.defaultExport !== "undefined"
+              ? options.defaultExport
+              : false;
+
+          return defaultExport
+            ? `${localsString}\n${exportsString}\nexport default { ${identifiers
+                .map(([id, key]) => `${JSON.stringify(key)}: ${id}`)
+                .join(", ")} }\n`
+            : `${localsString}\n${exportsString}\n`;
         }
 
         return `\n${

test/__snapshots__/validate-loader-options.test.js.snap

@@ -21,47 +21,47 @@ exports[`validate options should throw an error on the "publicPath" option with
 exports[`validate options should throw an error on the "unknown" option with "/test/" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;
 
 exports[`validate options should throw an error on the "unknown" option with "[]" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;
 
 exports[`validate options should throw an error on the "unknown" option with "{"foo":"bar"}" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;
 
 exports[`validate options should throw an error on the "unknown" option with "{}" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;
 
 exports[`validate options should throw an error on the "unknown" option with "1" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;
 
 exports[`validate options should throw an error on the "unknown" option with "false" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;
 
 exports[`validate options should throw an error on the "unknown" option with "test" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;
 
 exports[`validate options should throw an error on the "unknown" option with "true" value 1`] = `
 "Invalid options object. Mini CSS Extract Plugin Loader has been initialized using an options object that does not match the API schema.
  - options has an unknown property 'unknown'. These properties are valid:
-   object { publicPath?, emit?, esModule?, layer? }"
+   object { publicPath?, emit?, esModule?, layer?, defaultExport? }"
 `;

test/validate-loader-options.test.js

@@ -10,6 +10,10 @@ describe("validate options", () => {
       success: [true, false],
       failure: [1],
     },
+    defaultExport: {
+      success: [true, false],
+      failure: [1],
+    },
     unknown: {
       success: [],
       failure: [1, true, false, "test", /test/, [], {}, { foo: "bar" }],

types/index.d.ts

@@ -148,6 +148,7 @@ type PluginOptions = {
  * @property {boolean} [emit]
  * @property {boolean} [esModule]
  * @property {string} [layer]
+ * @property {boolean} [defaultExport]
  */
 /**
  * @typedef {Object} PluginOptions
@@ -200,6 +201,7 @@ type LoaderOptions = {
   emit?: boolean | undefined;
   esModule?: boolean | undefined;
   layer?: string | undefined;
+  defaultExport?: boolean | undefined;
 };
 type NormalizedPluginOptions = {
   filename: Required<Configuration>["output"]["filename"];