From 7be02b179ff082b5729b5a1ccdc20bf05f630412 Mon Sep 17 00:00:00 2001
From: Jonathan Ingram <jonathan.ingram@digital.gov.au>
Date: Tue, 14 Nov 2017 15:53:19 +1100
Subject: [PATCH] webpack: allow skins to add extra env variables

---
 webpack.config.js | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/webpack.config.js b/webpack.config.js
index dc731f5b..895c1408 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -9,6 +9,26 @@ const CG_STYLE_PATH = process.env.CG_STYLE_PATH;
 
 const SKIN_NAME = process.env.SKIN_NAME || 'cg';
 
+// getSkinEnv looks in the skin module for an `env.js` file which is expected to
+// contain an array of additional environment variable names that should be
+// added to the webpack DefinePlugin.
+// If the skin's env module is not found, an empty array is returned: this
+// makes the feature opt-in for skins.
+const getSkinEnv = () => {
+  const mod = path.resolve(
+    __dirname,
+    `static_src/skins/${SKIN_NAME}/env`
+  );
+
+  try {
+    require.resolve(mod);
+  } catch (e) {
+    return [];
+  }
+
+  return require(mod); // eslint-disable-line import/no-dynamic-require, global-require
+};
+
 const srcDir = './static_src';
 const compiledDir = './static/assets';
 
@@ -102,6 +122,12 @@ if (PRODUCTION) {
   processEnv.NODE_ENV = JSON.stringify('production');
 }
 
+const skinEnv = getSkinEnv();
+
+skinEnv.forEach((env) => {
+  processEnv[env] = JSON.stringify(process.env[env]);
+});
+
 config.plugins.push(
   new webpack.DefinePlugin({
     'process.env': processEnv