feat: linkType option

README.md

@@ -75,13 +75,14 @@ module.exports = {
 
 ### Plugin Options
 
-|                 Name                  |         Type         |                                     Default                                      | Description                                              |
-| :-----------------------------------: | :------------------: | :------------------------------------------------------------------------------: | :------------------------------------------------------- |
-|      **[`filename`](#filename)**      | `{String\|Function}` |                                   `[name].css`                                   | This option determines the name of each output CSS file  |
-| **[`chunkFilename`](#chunkFilename)** | `{String\|Function}` |                               `based on filename`                                | This option determines the name of non-entry chunk files |
-|   **[`ignoreOrder`](#ignoreOrder)**   |     `{Boolean}`      |                                     `false`                                      | Remove Order Warnings                                    |
-|        **[`insert`](#insert)**        | `{String\|Function}` | `var head = document.getElementsByTagName("head")[0];head.appendChild(linkTag);` | Inserts `<link>` at the given position                   |
-|    **[`attributes`](#attributes)**    |      `{Object}`      |                                       `{}`                                       | Adds custom attributes to tag                            |
+|                 Name                  |         Type         |                Default                | Description                                                |
+| :-----------------------------------: | :------------------: | :-----------------------------------: | :--------------------------------------------------------- |
+|      **[`filename`](#filename)**      | `{String\|Function}` |             `[name].css`              | This option determines the name of each output CSS file    |
+| **[`chunkFilename`](#chunkFilename)** | `{String\|Function}` |          `based on filename`          | This option determines the name of non-entry chunk files   |
+|   **[`ignoreOrder`](#ignoreOrder)**   |     `{Boolean}`      |                `false`                | Remove Order Warnings                                      |
+|        **[`insert`](#insert)**        | `{String\|Function}` | `document.head.appendChild(linkTag);` | Inserts `<link>` at the given position                     |
+|    **[`attributes`](#attributes)**    |      `{Object}`      |                 `{}`                  | Adds custom attributes to tag                              |
+|      **[`linkType`](#linkType)**      | `{String\|Boolean}`  |              `text/css`               | Allows loading asynchronous chunks with a custom link type |
 
 #### `filename`
 
@@ -114,7 +115,7 @@ See [examples](#remove-order-warnings) below for details.
 #### `insert`
 
 Type: `String|Function`
-Default: `var head = document.getElementsByTagName("head")[0]; head.appendChild(linkTag);`
+Default: `document.head.appendChild(linkTag);`
 
 By default, the `extract-css-chunks-plugin` appends styles (`<link>` elements) to `document.head` of the current `window`.
 
@@ -196,6 +197,65 @@ module.exports = {
 
 Note: It's only applied to dynamically loaded css chunks, if you want to modify link attributes inside html file, please using [html-webpack-plugin](/~https://github.com/jantimon/html-webpack-plugin)
 
+#### `linkType`
+
+Type: `String|Boolean`
+Default: `text/css`
+
+This option allows loading asynchronous chunks with a custom link type, such as <link type="text/css" ...>.
+
+##### `String`
+
+Possible values: `text/css`
+
+**webpack.config.js**
+
+```js
+const MiniCssExtractPlugin = require('mini-css-extract-plugin');
+
+module.exports = {
+  plugins: [
+    new MiniCssExtractPlugin({
+      linkType: 'text/css',
+    }),
+  ],
+  module: {
+    rules: [
+      {
+        test: /\.css$/i,
+        use: [MiniCssExtractPlugin.loader, 'css-loader'],
+      },
+    ],
+  },
+};
+```
+
+##### `Boolean`
+
+`false` disables the link `type` attribute
+
+**webpack.config.js**
+
+```js
+const MiniCssExtractPlugin = require('mini-css-extract-plugin');
+
+module.exports = {
+  plugins: [
+    new MiniCssExtractPlugin({
+      linkType: false,
+    }),
+  ],
+  module: {
+    rules: [
+      {
+        test: /\.css$/i,
+        use: [MiniCssExtractPlugin.loader, 'css-loader'],
+      },
+    ],
+  },
+};
+```
+
 ### Loader Options
 
 |              Name               |         Type         |              Default               | Description                                                                       |

src/CssLoadingRuntimeModule.js

@@ -57,7 +57,9 @@ module.exports = class CssLoadingRuntimeModule extends RuntimeModule {
           'var linkTag = document.createElement("link");',
           this.runtimeOptions.attributes,
           'linkTag.rel = "stylesheet";',
-          'linkTag.type = "text/css";',
+          this.runtimeOptions.linkType
+            ? `linkTag.type = ${JSON.stringify(this.runtimeOptions.linkType)};`
+            : '',
           'linkTag.onload = resolve;',
           'linkTag.onerror = function(event) {',
           Template.indent([

src/index.js

@@ -44,14 +44,17 @@ class MiniCssExtractPlugin {
               `var target = document.querySelector("${options.insert}");`,
               `target.parentNode.insertBefore(linkTag, target.nextSibling);`,
             ])
-        : Template.asString([
-            'var head = document.getElementsByTagName("head")[0];',
-            'head.appendChild(linkTag);',
-          ]);
+        : Template.asString(['document.head.appendChild(linkTag);']);
 
     const attributes =
       typeof options.attributes === 'object' ? options.attributes : {};
 
+    // Todo in next major release set default to "false"
+    const linkType =
+      options.linkType === true || typeof options.linkType === 'undefined'
+        ? 'text/css'
+        : options.linkType;
+
     this.options = Object.assign(
       {
         filename: DEFAULT_FILENAME,
@@ -62,6 +65,7 @@ class MiniCssExtractPlugin {
 
     this.runtimeOptions = {
       insert,
+      linkType,
     };
 
     this.runtimeOptions.attributes = Template.asString(
@@ -398,7 +402,11 @@ class MiniCssExtractPlugin {
                     'var linkTag = document.createElement("link");',
                     this.runtimeOptions.attributes,
                     'linkTag.rel = "stylesheet";',
-                    'linkTag.type = "text/css";',
+                    this.runtimeOptions.linkType
+                      ? `linkTag.type = ${JSON.stringify(
+                          this.runtimeOptions.linkType
+                        )};`
+                      : '',
                     'linkTag.onload = resolve;',
                     'linkTag.onerror = function(event) {',
                     Template.indent([

src/plugin-options.json

@@ -39,6 +39,16 @@
     "attributes": {
       "description": "Adds custom attributes to tag (/~https://github.com/webpack-contrib/mini-css-extract-plugin#attributes).",
       "type": "object"
+    },
+    "linkType": {
+      "anyOf": [
+        {
+          "enum": ["text/css"]
+        },
+        {
+          "type": "boolean"
+        }
+      ]
     }
   }
 }

test/__snapshots__/linkTag-option.test.js.snap

@@ -0,0 +1,55 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`linkType option should work when linkType option is "false": DOM 1`] = `
+"<!DOCTYPE html><html><head>
+  <title>style-loader test</title>
+  <style id=\\"existing-style\\">.existing { color: yellow }</style>
+<link rel=\\"stylesheet\\" href=\\"simple.css\\"><script charset=\\"utf-8\\" src=\\"simple.bundle.js\\"></script></head>
+<body>
+  <h1>Body</h1>
+  <div class=\\"target\\"></div>
+  <iframe class=\\"iframeTarget\\"></iframe>
+
+
+</body></html>"
+`;
+
+exports[`linkType option should work when linkType option is "false": errors 1`] = `Array []`;
+
+exports[`linkType option should work when linkType option is "false": warnings 1`] = `Array []`;
+
+exports[`linkType option should work when linkType option is "text/css": DOM 1`] = `
+"<!DOCTYPE html><html><head>
+  <title>style-loader test</title>
+  <style id=\\"existing-style\\">.existing { color: yellow }</style>
+<link rel=\\"stylesheet\\" type=\\"text/css\\" href=\\"simple.css\\"><script charset=\\"utf-8\\" src=\\"simple.bundle.js\\"></script></head>
+<body>
+  <h1>Body</h1>
+  <div class=\\"target\\"></div>
+  <iframe class=\\"iframeTarget\\"></iframe>
+
+
+</body></html>"
+`;
+
+exports[`linkType option should work when linkType option is "text/css": errors 1`] = `Array []`;
+
+exports[`linkType option should work when linkType option is "text/css": warnings 1`] = `Array []`;
+
+exports[`linkType option should work without linkType option: DOM 1`] = `
+"<!DOCTYPE html><html><head>
+  <title>style-loader test</title>
+  <style id=\\"existing-style\\">.existing { color: yellow }</style>
+<link rel=\\"stylesheet\\" type=\\"text/css\\" href=\\"simple.css\\"><script charset=\\"utf-8\\" src=\\"simple.bundle.js\\"></script></head>
+<body>
+  <h1>Body</h1>
+  <div class=\\"target\\"></div>
+  <iframe class=\\"iframeTarget\\"></iframe>
+
+
+</body></html>"
+`;
+
+exports[`linkType option should work without linkType option: errors 1`] = `Array []`;
+
+exports[`linkType option should work without linkType option: warnings 1`] = `Array []`;

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

@@ -59,3 +59,39 @@ exports[`validate options should throw an error on the "insert" option with "tru
     * options.insert should be a string.
     * options.insert should be an instance of function."
 `;
+
+exports[`validate options should throw an error on the "linkType" option with "[]" value 1`] = `
+"Invalid options object. Mini CSS Extract Plugin has been initialized using an options object that does not match the API schema.
+ - options.linkType should be one of these:
+   \\"text/css\\" | boolean
+   Details:
+    * options.linkType should be \\"text/css\\".
+    * options.linkType should be a boolean."
+`;
+
+exports[`validate options should throw an error on the "linkType" option with "{}" value 1`] = `
+"Invalid options object. Mini CSS Extract Plugin has been initialized using an options object that does not match the API schema.
+ - options.linkType should be one of these:
+   \\"text/css\\" | boolean
+   Details:
+    * options.linkType should be \\"text/css\\".
+    * options.linkType should be a boolean."
+`;
+
+exports[`validate options should throw an error on the "linkType" option with "1" value 1`] = `
+"Invalid options object. Mini CSS Extract Plugin has been initialized using an options object that does not match the API schema.
+ - options.linkType should be one of these:
+   \\"text/css\\" | boolean
+   Details:
+    * options.linkType should be \\"text/css\\".
+    * options.linkType should be a boolean."
+`;
+
+exports[`validate options should throw an error on the "linkType" option with "invalid/type" value 1`] = `
+"Invalid options object. Mini CSS Extract Plugin has been initialized using an options object that does not match the API schema.
+ - options.linkType should be one of these:
+   \\"text/css\\" | boolean
+   Details:
+    * options.linkType should be \\"text/css\\".
+    * options.linkType should be a boolean."
+`;

test/cases/hmr/expected/webpack-5/main.js

@@ -838,8 +838,7 @@ module.exports = function (urlString) {
 /******/ 			};
 /******/ 			linkTag.href = fullhref;
 /******/ 		
-/******/ 			var head = document.getElementsByTagName("head")[0];
-/******/ 			head.appendChild(linkTag);
+/******/ 			document.head.appendChild(linkTag);
 /******/ 			return linkTag;
 /******/ 		};
 /******/ 		var findStylesheet = (href, fullhref) => {

test/cases/insert-undefined/expected/webpack-4/main.js

@@ -116,8 +116,7 @@
 /******/ 				};
 /******/ 				linkTag.href = fullhref;
 /******/
-/******/ 				var head = document.getElementsByTagName("head")[0];
-/******/ 				head.appendChild(linkTag);
+/******/ 				document.head.appendChild(linkTag);
 /******/ 			}).then(function() {
 /******/ 				installedCssChunks[chunkId] = 0;
 /******/ 			}));

test/cases/insert-undefined/expected/webpack-5/main.js

@@ -173,8 +173,7 @@
 /******/ 			};
 /******/ 			linkTag.href = fullhref;
 /******/ 		
-/******/ 			var head = document.getElementsByTagName("head")[0];
-/******/ 			head.appendChild(linkTag);
+/******/ 			document.head.appendChild(linkTag);
 /******/ 			return linkTag;
 /******/ 		};
 /******/ 		var findStylesheet = (href, fullhref) => {

test/linkTag-option.test.js

@@ -0,0 +1,97 @@
+/* eslint-env browser */
+import path from 'path';
+
+import MiniCssExtractPlugin from '../src/cjs';
+
+import {
+  compile,
+  getCompiler,
+  getErrors,
+  getWarnings,
+  runInJsDom,
+} from './helpers/index';
+
+describe('linkType option', () => {
+  it(`should work without linkType option`, async () => {
+    const compiler = getCompiler(
+      'attributes.js',
+      {},
+      {
+        output: {
+          publicPath: '',
+          path: path.resolve(__dirname, '../outputs'),
+          filename: '[name].bundle.js',
+        },
+        plugins: [
+          new MiniCssExtractPlugin({
+            filename: '[name].css',
+          }),
+        ],
+      }
+    );
+    const stats = await compile(compiler);
+
+    runInJsDom('main.bundle.js', compiler, stats, (dom) => {
+      expect(dom.serialize()).toMatchSnapshot('DOM');
+    });
+
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+  });
+
+  it(`should work when linkType option is "false"`, async () => {
+    const compiler = getCompiler(
+      'attributes.js',
+      {},
+      {
+        output: {
+          publicPath: '',
+          path: path.resolve(__dirname, '../outputs'),
+          filename: '[name].bundle.js',
+        },
+        plugins: [
+          new MiniCssExtractPlugin({
+            linkType: false,
+            filename: '[name].css',
+          }),
+        ],
+      }
+    );
+    const stats = await compile(compiler);
+
+    runInJsDom('main.bundle.js', compiler, stats, (dom) => {
+      expect(dom.serialize()).toMatchSnapshot('DOM');
+    });
+
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+  });
+
+  it(`should work when linkType option is "text/css"`, async () => {
+    const compiler = getCompiler(
+      'attributes.js',
+      {},
+      {
+        output: {
+          publicPath: '',
+          path: path.resolve(__dirname, '../outputs'),
+          filename: '[name].bundle.js',
+        },
+        plugins: [
+          new MiniCssExtractPlugin({
+            linkType: 'text/css',
+            filename: '[name].css',
+          }),
+        ],
+      }
+    );
+    const stats = await compile(compiler);
+
+    runInJsDom('main.bundle.js', compiler, stats, (dom) => {
+      expect(dom.serialize()).toMatchSnapshot('DOM');
+    });
+
+    expect(getWarnings(stats)).toMatchSnapshot('warnings');
+    expect(getErrors(stats)).toMatchSnapshot('errors');
+  });
+});