Merge pull request #186 from halfzebra/disablinb-dead-code-elimination

feat($config): Enable users to disable dead code elimination by setti…
halfzebra · Oct 31, 2017 · 0486adf · 0486adf
2 parents 3813c89 + a7493be
commit 0486adf
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Showing 2 changed files with 40 additions and 23 deletions.
diff --git a/config/webpack.config.prod.js b/config/webpack.config.prod.js
@@ -37,6 +37,33 @@ const extractTextPluginOptions = shouldUseRelativeAssetPaths
     { publicPath: Array(cssFilename.split('/').length).join('../') }
   : {};
 
+// Enable users to turn off dead code elimination.
+const deadCodeElimination =
+  process.env.DEAD_CODE_ELIMINATION !== 'true'
+    ? {
+        dead_code: true,
+        pure_funcs: [
+          '_elm_lang$core$Native_Utils.update',
+          'A2',
+          'A3',
+          'A4',
+          'A5',
+          'A6',
+          'A7',
+          'A8',
+          'A9',
+          'F2',
+          'F3',
+          'F4',
+          'F5',
+          'F6',
+          'F7',
+          'F8',
+          'F9'
+        ]
+      }
+    : {};
+
 module.exports = {
   // Don't attempt to continue if there are any errors.
   bail: true,
@@ -185,29 +212,12 @@ module.exports = {
 
     // Minify the compiled JavaScript.
     new UglifyJsPlugin({
-      compress: {
-        warnings: false,
-        dead_code: true,
-        pure_funcs: [
-          '_elm_lang$core$Native_Utils.update',
-          'A2',
-          'A3',
-          'A4',
-          'A5',
-          'A6',
-          'A7',
-          'A8',
-          'A9',
-          'F2',
-          'F3',
-          'F4',
-          'F5',
-          'F6',
-          'F7',
-          'F8',
-          'F9'
-        ]
-      },
+      compress: Object.assign(
+        {
+          warnings: false
+        },
+        deadCodeElimination
+      ),
       output: {
         comments: false
       }

diff --git a/template/README.md b/template/README.md
@@ -20,6 +20,7 @@ You can find the most recent version of this guide [here](https://github.com/hal
     - [make](#make)
     - [reactor](#reactor)
 - [Turning on/off Elm Debugger](#turning-onoff-elm-debugger)
+- [Dead code elimination](#dead-code-elimination)
 - [Changing the Page `<title>`](#changing-the-page-title)
 - [Adding a Stylesheet](#adding-a-stylesheet)
 - [Post-Processing CSS](#post-processing-css)
@@ -168,6 +169,12 @@ By default, in production (`elm-app build`) the Debugger is turned off and in de
 
 To turn on/off Elm Debugger explicitly, set `ELM_DEBUGGER` environment variable to `true` or `false` respectively.
 
+## Dead code elimination
+
+Create Elm App comes with an opinionated setup for dead code elimination which is disabled by default, because it may break your code.
+
+You can enable it by setting `DEAD_CODE_ELIMINATION` environment variable to `true`
+
 ## Changing the base path of the assets in the HTML
 
 By default, assets will be linked from the HTML to the root url. For example `/css/style.css`.