Merge pull request #529 from ipfs-shipyard/fix/pubsub-in-js-ipfs

Change webpack minimizer flags to follow Aegir

### Problem fixed by this PR

Default minimizer flags break pubsub with embedded node  by removing 'unused' code of pubsub experiment. Details in #521.

### In This PR

-  Backport of ipfs/aegir#214: it restores pubsub functionality and applies the fix for  entire build pipeline to avoid similar issues in future.
- The way configuration blocks are merged is improved by use of [webpack-merge](https://www.npmjs.com/package/webpack-merge)
- Bundles are bit smaller due to moving LICENSE comments to separate file (`extractComments: true`)

package.json

@@ -79,7 +79,8 @@
     "web-ext": "2.7.0",
     "webpack": "4.14.0",
     "webpack-bundle-analyzer": "2.13.1",
-    "webpack-cli": "3.0.8"
+    "webpack-cli": "3.0.8",
+    "webpack-merge": "4.1.3"
   },
   "dependencies": {
     "choo": "6.12.1",

webpack.config.js

@@ -1,6 +1,8 @@
 const path = require('path')
 const webpack = require('webpack')
+const merge = require('webpack-merge')
 const SimpleProgressWebpackPlugin = require('simple-progress-webpack-plugin')
+const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
 // const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin;
 
 // common configuration shared by all targets
@@ -12,6 +14,19 @@ const commonConfig = {
     publicPath: '/dist/bundles/',
     filename: '[name].bundle.js'
   },
+  optimization: {
+    minimizer: [
+      // Default flags break js-ipfs: https://github.com/ipfs-shipyard/ipfs-companion/issues/521
+      new UglifyJsPlugin({
+        parallel: true,
+        extractComments: true,
+        uglifyOptions: {
+          compress: { unused: false },
+          mangle: true
+        }
+      })
+    ]
+  },
   // plugins: [new BundleAnalyzerPlugin()]
   plugins: [
     new SimpleProgressWebpackPlugin({
@@ -47,7 +62,7 @@ const commonConfig = {
 }
 
 // background page bundle (with heavy dependencies)
-const bgConfig = Object.assign({}, commonConfig, {
+const bgConfig = merge(commonConfig, {
   name: 'background',
   entry: {
     backgroundPage: './add-on/src/background/background.js'
@@ -71,7 +86,7 @@ const bgConfig = Object.assign({}, commonConfig, {
 })
 
 // user interface pages with shared common libraries
-const uiConfig = Object.assign({}, commonConfig, {
+const uiConfig = merge(commonConfig, {
   name: 'ui',
   entry: {
     browserAction: './add-on/src/popup/browser-action/index.js',
@@ -100,7 +115,7 @@ const uiConfig = Object.assign({}, commonConfig, {
 })
 
 // content scripts injected into tabs
-const contentScriptsConfig = Object.assign({}, commonConfig, {
+const contentScriptsConfig = merge(commonConfig, {
   name: 'contentScripts',
   entry: {
     ipfsProxyContentScriptPayload: './add-on/src/contentScripts/ipfs-proxy/page.js',
@@ -111,7 +126,7 @@ const contentScriptsConfig = Object.assign({}, commonConfig, {
 
 // special content script that injects window.ipfs into REAL window object
 // (by default scripts executed via tabs.executeScript get a sandbox version)
-const proxyContentScriptConfig = Object.assign({}, commonConfig, {
+const proxyContentScriptConfig = merge(commonConfig, {
   name: 'proxyContentScript',
   dependencies: ['contentScripts'],
   entry: {

yarn.lock

@@ -10726,6 +10726,12 @@ webpack-cli@3.0.8:
     v8-compile-cache "^2.0.0"
     yargs "^11.1.0"
 
+webpack-merge@4.1.3:
+  version "4.1.3"
+  resolved "https://registry.yarnpkg.com/webpack-merge/-/webpack-merge-4.1.3.tgz#8aaff2108a19c29849bc9ad2a7fd7fce68e87c4a"
+  dependencies:
+    lodash "^4.17.5"
+
 webpack-sources@^1.0.1, webpack-sources@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/webpack-sources/-/webpack-sources-1.1.0.tgz#a101ebae59d6507354d71d8013950a3a8b7a5a54"