fix: bloated runtime (#687)

Author: alexander-akait

Diff for: src/index.js

@@ -477,10 +477,15 @@ class MiniCssExtractPlugin {
               MODULE_TYPE,
               'mini-css',
               `${webpack.RuntimeGlobals.require}.miniCssF`,
-              (referencedChunk) =>
-                referencedChunk.canBeInitial()
+              (referencedChunk) => {
+                if (!referencedChunk.contentHash[MODULE_TYPE]) {
+                  return false;
+                }
+
+                return referencedChunk.canBeInitial()
                   ? this.options.filename
-                  : this.options.chunkFilename,
+                  : this.options.chunkFilename;
+              },
               true
             )
           );

Diff for: test/cases/hmr/expected/webpack-5/main.js

@@ -358,7 +358,7 @@ module.exports = function (urlString) {
 /******/ 		// This function allow to reference all chunks
 /******/ 		__webpack_require__.miniCssF = (chunkId) => {
 /******/ 			// return url for filenames based on template
-/******/ 			return "" + "main" + ".css";
+/******/ 			return undefined;
 /******/ 		};
 /******/ 	})();
 /******/ 	

Diff for: test/cases/hmr/webpack.config.js

@@ -4,6 +4,7 @@ import Self from '../../../src';
 
 module.exports = {
   entry: './index.css',
+  mode: 'development',
   module: {
     rules: [
       {

Diff for: test/cases/insert-function/expected/webpack-5/main.js

@@ -54,10 +54,8 @@
 /******/ 	(() => {
 /******/ 		// This function allow to reference all chunks
 /******/ 		__webpack_require__.miniCssF = (chunkId) => {
-/******/ 			// return url for filenames not based on template
-/******/ 			if (chunkId === 1) return "1.css";
 /******/ 			// return url for filenames based on template
-/******/ 			return "" + "main" + ".css";
+/******/ 			return "" + chunkId + ".css";
 /******/ 		};
 /******/ 	})();
 /******/ 	

Diff for: test/cases/insert-string/expected/webpack-5/main.js

@@ -54,10 +54,8 @@
 /******/ 	(() => {
 /******/ 		// This function allow to reference all chunks
 /******/ 		__webpack_require__.miniCssF = (chunkId) => {
-/******/ 			// return url for filenames not based on template
-/******/ 			if (chunkId === 1) return "1.css";
 /******/ 			// return url for filenames based on template
-/******/ 			return "" + "main" + ".css";
+/******/ 			return "" + chunkId + ".css";
 /******/ 		};
 /******/ 	})();
 /******/ 	

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

@@ -54,10 +54,8 @@
 /******/ 	(() => {
 /******/ 		// This function allow to reference all chunks
 /******/ 		__webpack_require__.miniCssF = (chunkId) => {
-/******/ 			// return url for filenames not based on template
-/******/ 			if (chunkId === 1) return "1.css";
 /******/ 			// return url for filenames based on template
-/******/ 			return "" + "main" + ".css";
+/******/ 			return "" + chunkId + ".css";
 /******/ 		};
 /******/ 	})();
 /******/ 	

Diff for: test/cases/runtime/expected/webpack-5/runtime~main.js

@@ -101,7 +101,7 @@
 /******/ 		// This function allow to reference all chunks
 /******/ 		__webpack_require__.miniCssF = (chunkId) => {
 /******/ 			// return url for filenames based on template
-/******/ 			return "" + ({"0":"main","1":"runtime~main"}[chunkId] || chunkId) + "." + {"0":"a7263f8f763dcf4051bc"}[chunkId] + ".css";
+/******/ 			return "" + "main" + "." + "a7263f8f763dcf4051bc" + ".css";
 /******/ 		};
 /******/ 	})();
 /******/