Use babel-minify to optimize the supervisor code

We've been using UglifyJS (the webpack default) so far, but this doesn't support ES6 and some dependency
updates are starting to cause builds to break (e.g. request/request#2772, which also happens to break
my builds in the multicontainer branch).

Here we switch to using babel-minify which is designed for ES2015 support. I had to disable the "mangle" option
because some dependencies break when mangled by babel-minify (which is a bit mysterious since it should
be able to handle them well, but there's at least one case where an eval() in a dependency breaks the supervisor).
This adds ~800kB to the resulting uncompressed image.

Since the optimization now happens with a plugin instead of the webpack command line,
we can't do the no-optimize trick we were doing in dindctl now - but it should
also be less important now that we don't mangle names.

Change-Type: patch
Signed-off-by: Pablo Carranza Velez <pablo@resin.io>

dindctl

@@ -49,7 +49,6 @@ DIST_MOUNTED="false"
 DIND_IMAGE="resin-supervisor-dind"
 CONTAINER_NAME="resin_supervisor_1"
 PRELOADED_IMAGE=""
-OPTIMIZE="true"
 CONFIG_FILENAME="config.json"
 
 function showHelp {
@@ -93,9 +92,6 @@ function parseOptions {
 				ARCH="$2"
 				shift || { echo "--arch provided not specified" && exit 1; }
 				;;
-			--no-optimize)
-				OPTIMIZE="false"
-				;;
 			*)
 				echo "Warning: unknown argument: $arg"
 				;;
@@ -113,13 +109,8 @@ function buildSupervisor {
 }
 
 function buildSupervisorSrc {
-	if [ "$OPTIMIZE" = "true" ]; then
-		echo "Rebuilding supervisor source"
-		( cd "$SUPERVISOR_BASE_DIR" && npm install && npm run build )
-	else
-		echo "Rebuilding supervisor source without optimizations"
-		( cd "$SUPERVISOR_BASE_DIR" && npm install && npm run build-no-optimize )
-	fi
+	echo "Rebuilding supervisor source"
+	( cd "$SUPERVISOR_BASE_DIR" && npm install && npm run build )
 }
 
 function refreshSupervisorSrc {

package.json

@@ -9,8 +9,7 @@
   },
   "scripts": {
     "start": "./entry.sh",
-    "build": "webpack --optimize-minimize",
-    "build-no-optimize": "webpack",
+    "build": "webpack",
     "lint": "resin-lint src/",
     "versionist": "versionist"
   },
@@ -23,6 +22,7 @@
   },
   "devDependencies": {
     "JSONStream": "^1.1.2",
+    "babel-minify-webpack-plugin": "^0.2.0",
     "blinking": "~0.0.2",
     "bluebird": "^3.5.0",
     "body-parser": "^1.12.0",
@@ -59,4 +59,4 @@
     "versionist": "^2.8.0",
     "webpack": "^3.0.0"
   }
-}
+}

webpack.config.js

@@ -2,7 +2,8 @@ var webpack = require('webpack');
 var path = require('path');
 var fs = require('fs');
 var _ = require('lodash');
-var path = require('path')
+var path = require('path');
+var MinifyPlugin = require("babel-minify-webpack-plugin");
 
 var externalModules = [
 	'mkfifo',
@@ -84,6 +85,11 @@ module.exports = {
 	plugins: [
 		new webpack.DefinePlugin({
 			'process.env.NODE_ENV': '"production"',
+		}),
+		new MinifyPlugin({
+			mangle: false,
+			keepFnName: true,
+			keepClassName: true
 		})
 	]
 };