fix: issue 701

src/index.js

@@ -280,6 +280,8 @@ class MiniCssExtractPlugin {
       baseDataPath: 'options',
     });
 
+    this._sortedModulesCache = new WeakMap();
+
     this.options = Object.assign(
       { filename: DEFAULT_FILENAME, ignoreOrder: false },
       options
@@ -535,7 +537,15 @@ class MiniCssExtractPlugin {
           ? Array.from(this.getChunkModules(chunk, chunkGraph)).filter(
               (module) => module.type === MODULE_TYPE
             )
-          : chunkGraph.getChunkModulesIterableBySourceType(chunk, MODULE_TYPE);
+          : this.sortModules(
+              compilation,
+              chunk,
+              chunkGraph.getChunkModulesIterableBySourceType(
+                chunk,
+                MODULE_TYPE
+              ),
+              compilation.runtimeTemplate.requestShortener
+            );
 
         if (modules) {
           const { hashFunction, hashDigest, hashDigestLength } = outputOptions;
@@ -1076,8 +1086,14 @@ class MiniCssExtractPlugin {
     return obj;
   }
 
-  renderContentAsset(compiler, compilation, chunk, modules, requestShortener) {
-    let usedModules;
+  sortModules(compilation, chunk, modules, requestShortener) {
+    let usedModules = this._sortedModulesCache.get(chunk);
+
+    if (usedModules || !modules) {
+      return usedModules;
+    }
+
+    modules = [...modules];
 
     const [chunkGroup] = chunk.groupsIterable;
     const moduleIndexFunctionName =
@@ -1215,6 +1231,19 @@ class MiniCssExtractPlugin {
       usedModules = modules;
     }
 
+    this._sortedModulesCache.set(chunk, usedModules);
+
+    return usedModules;
+  }
+
+  renderContentAsset(compiler, compilation, chunk, modules, requestShortener) {
+    const usedModules = this.sortModules(
+      compilation,
+      chunk,
+      modules,
+      requestShortener
+    );
+
     // TODO remove after drop webpack v4
     const { ConcatSource, SourceMapSource, RawSource } = compiler.webpack
       ? compiler.webpack.sources

test/TestCache.test.js

@@ -167,7 +167,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler1.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });
@@ -207,7 +209,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler2.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });
@@ -274,7 +278,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler1.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });
@@ -316,7 +322,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler2.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });
@@ -385,7 +393,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler1.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });
@@ -428,7 +438,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler2.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });
@@ -497,7 +509,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler1.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });
@@ -540,7 +554,9 @@ describe('TestCache', () => {
           expect(stats.compilation.errors).toHaveLength(0);
 
           compiler2.close(() => {
-            resolve();
+            process.nextTick(() => {
+              resolve();
+            });
           });
         });
       });

test/cases/content-entries-with-same-import/expected/1.a2e2caac15fbc316194f.css

@@ -0,0 +1,8 @@
+.a {
+  width: 100px;
+}
+
+.b {
+  width: 100px;
+}
+

test/cases/content-entries-with-same-import/expected/2.b93278edf8733a516ab1.css

@@ -0,0 +1,8 @@
+.b {
+  width: 100px;
+}
+
+.a {
+  width: 100px;
+}
+

test/cases/content-entries-with-same-import/index.js

@@ -0,0 +1,7 @@
+const app1 = import('./one');
+const app2 = import('./two');
+
+// eslint-disable-next-line no-console
+console.log(app1);
+// eslint-disable-next-line no-console
+console.log(app2);

test/cases/content-entries-with-same-import/one.js

@@ -0,0 +1,4 @@
+import './style1.css';
+import './style2.css';
+
+export default 'one';

test/cases/content-entries-with-same-import/style1.css

@@ -0,0 +1,3 @@
+.a {
+  width: 100px;
+}

test/cases/content-entries-with-same-import/style2.css

@@ -0,0 +1,3 @@
+.b {
+  width: 100px;
+}

test/cases/content-entries-with-same-import/test.filter.js

@@ -0,0 +1,3 @@
+const webpack = require('webpack');
+
+module.exports = () => webpack.version[0] !== '4';

test/cases/content-entries-with-same-import/two.js

@@ -0,0 +1,4 @@
+import './style2.css';
+import './style1.css';
+
+export default 'two';

test/cases/content-entries-with-same-import/webpack.config.js

@@ -0,0 +1,21 @@
+import Self from '../../../src';
+
+module.exports = {
+  entry: './index.js',
+  module: {
+    rules: [
+      {
+        test: /\.css$/,
+        use: [Self.loader, 'css-loader'],
+      },
+    ],
+  },
+  output: {
+    filename: '[name].[contenthash].js',
+  },
+  plugins: [
+    new Self({
+      filename: '[name].[contenthash].css',
+    }),
+  ],
+};