support incremental build

package.json

@@ -44,7 +44,7 @@
     "nsp": "^3.1.0",
     "pre-commit": "^1.2.2",
     "standard-version": "^4.3.0",
-    "webpack": "^4.3.0",
+    "webpack": "^4.4.0",
     "webpack-cli": "^2.0.13",
     "webpack-defaults": "^1.6.0",
     "webpack-dev-server": "^3.1.1"
@@ -56,7 +56,7 @@
     "node": ">= 6.11.5"
   },
   "peerDependencies": {
-    "webpack": "^4.3.0"
+    "webpack": "^4.4.0"
   },
   "pre-commit": "lint-staged",
   "lint-staged": {

src/index.js

@@ -10,6 +10,10 @@ const NS = path.dirname(fs.realpathSync(__filename));
 
 const pluginName = 'mini-css-extract-plugin';
 
+const REGEXP_CHUNKHASH = /\[chunkhash(?::(\d+))?\]/i;
+const REGEXP_CONTENTHASH = /\[contenthash(?::(\d+))?\]/i;
+const REGEXP_NAME = /\[name\]/i;
+
 class CssDependency extends webpack.Dependency {
   constructor({ identifier, content, media, sourceMap }, context, identifierIndex) {
     super();
@@ -61,6 +65,16 @@ class CssModule extends webpack.Module {
     return resource;
   }
 
+  updateCacheModule(module) {
+    this.content = module.content;
+    this.media = module.media;
+    this.sourceMap = module.sourceMap;
+  }
+
+  needRebuild() {
+    return true;
+  }
+
   build(options, compilation, resolver, fileSystem, callback) {
     this.buildInfo = {};
     this.buildMeta = {};
@@ -131,6 +145,7 @@ class MiniCssExtractPlugin {
               contentHashType: NS,
             },
             identifier: `mini-css-extract-plugin.${chunk.id}`,
+            hash: chunk.contentHash[NS],
           });
         }
       });
@@ -145,9 +160,29 @@ class MiniCssExtractPlugin {
               contentHashType: NS,
             },
             identifier: `mini-css-extract-plugin.${chunk.id}`,
+            hash: chunk.contentHash[NS],
           });
         }
       });
+      compilation.mainTemplate.hooks.hashForChunk.tap(
+        pluginName,
+        (hash, chunk) => {
+          const { chunkFilename } = this.options;
+          if (REGEXP_CHUNKHASH.test(chunkFilename)) {
+            hash.update(JSON.stringify(chunk.getChunkMaps(true).hash));
+          }
+          if (REGEXP_CONTENTHASH.test(chunkFilename)) {
+            hash.update(
+              JSON.stringify(
+                chunk.getChunkMaps(true).contentHash[NS] || {},
+              ),
+            );
+          }
+          if (REGEXP_NAME.test(chunkFilename)) {
+            hash.update(JSON.stringify(chunk.getChunkMaps(true).name));
+          }
+        },
+      );
       compilation.hooks.contentHash.tap(pluginName, (chunk) => {
         const { outputOptions } = compilation;
         const { hashFunction, hashDigest, hashDigestLength } = outputOptions;

test/manual/webpack.config.js

@@ -3,6 +3,7 @@ const Self = require('../../');
 module.exports = {
   mode: 'development',
   output: {
+    chunkFilename: "[contenthash].js",
     publicPath: '/dist/',
   },
   module: {
@@ -19,6 +20,7 @@ module.exports = {
   plugins: [
     new Self({
       filename: '[name].css',
+      chunkFilename: "[contenthash].css",
     }),
   ],
   devServer: {