From 1889cdec6eeee264bb762229b527fa99eccfa6a7 Mon Sep 17 00:00:00 2001
From: Pan <panfree23@gmail.com>
Date: Wed, 8 Aug 2018 14:20:01 +0800
Subject: [PATCH] refine NamedChunksPlugin

---
 build/webpack.prod.conf.js | 27 +++++++++++++++++----------
 package.json               |  1 +
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/build/webpack.prod.conf.js b/build/webpack.prod.conf.js
index 42feb1f5..1e8f5bed 100644
--- a/build/webpack.prod.conf.js
+++ b/build/webpack.prod.conf.js
@@ -11,21 +11,17 @@ const ScriptExtHtmlWebpackPlugin = require('script-ext-html-webpack-plugin')
 const MiniCssExtractPlugin = require('mini-css-extract-plugin')
 const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin')
 const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
-const crypto = require('crypto');
-
 
 function resolve(dir) {
   return path.join(__dirname, '..', dir)
 }
 
-function createHash(data) {
-  const length = 8
-  const hash = crypto.createHash('md5').update(data).digest("hex")
-  return hash.slice(0, length)
-}
-
 const env = require('../config/' + process.env.env_config + '.env')
 
+// For NamedChunksPlugin
+const seen = new Set();
+const nameLength = 4;
+
 const webpackConfig = merge(baseWebpackConfig, {
   mode: 'production',
   module: {
@@ -76,11 +72,22 @@ const webpackConfig = merge(baseWebpackConfig, {
       //`runtime` must same as runtimeChunk name. default is `runtime`
       inline: /runtime\..*\.js$/
     }),
+    // keep chunk.id stable when chunk has no name
     new webpack.NamedChunksPlugin(chunk => {
       if (chunk.name) {
-        return chunk.name
+        return chunk.name;
+      }
+      const modules = Array.from(chunk.modulesIterable);
+      if (modules.length > 1) {
+        const hash = require("hash-sum");
+        const joinedHash = hash(modules.map(m => m.id).join("_"));
+        let len = nameLength;
+        while (seen.has(joinedHash.substr(0, len))) len++;
+        seen.add(joinedHash.substr(0, len));
+        return `chunk-${joinedHash.substr(0, len)}`;
+      } else {
+        return modules[0].id;
       }
-      return createHash(Array.from(chunk.modulesIterable, m => m.id).join('_'))
     }),
     // keep module.id stable when vender modules does not change
     new webpack.HashedModuleIdsPlugin(),
diff --git a/package.json b/package.json
index f8a91591..738a663b 100644
--- a/package.json
+++ b/package.json
@@ -85,6 +85,7 @@
     "eslint-plugin-html": "4.0.5",
     "file-loader": "1.1.11",
     "friendly-errors-webpack-plugin": "1.7.0",
+    "hash-sum": "^1.0.2",
     "html-webpack-plugin": "^4.0.0-alpha",
     "husky": "0.14.3",
     "lint-staged": "7.2.0",