Expand .env variables

Author: grgur

README.md

@@ -2,6 +2,29 @@
 
 Monorepo containing setup for a best-practice React application scaffolding
 
+### ENV variables
+
+You can use environment variables to configure build scripts.
+
+Here's the list of supported variables with their defaults:
+
+```
+SOURCE_DIR=src
+BUILD_DIR=build
+SOURCEMAPS=false
+```
+
+You can override any of these variables with `.env` files. We support these formats (in the order of inclusion):
+
+```
+.env.${NODE_ENV}.local
+.env.${NODE_ENV}
+.env.local
+.env
+```
+
+The order of inclusion means that anything in `.env` will override content in e.g. `.env.development.local`.
+
 ### DLLs
 
 DLLs precompile libraries to save time for development builds and re-builds.

packages/more/package.json

@@ -3,6 +3,9 @@
   "version": "0.0.4",
   "description": "Modus React App Scaffolding",
   "bin": "bin/more.js",
+  "engines": {
+    "node": ">=8.9.3"
+  },
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"
   },
@@ -23,6 +26,7 @@
     "cross-spawn": "^6.0.5",
     "css-loader": "1.0.1",
     "dotenv": "^6.2.0",
+    "dotenv-expand": "^4.2.0",
     "eslint": "5.9.0",
     "file-loader": "2.0.0",
     "find-file-up": "^2.0.1",

packages/more/utils/env.js

@@ -1,10 +1,26 @@
+const fs = require('fs');
 const path = require('path');
-const find = require('find-file-up');
+const expand = require('dotenv-expand');
+const dotenv = require('dotenv');
 
-// Find .env or .env.local
-const envFile =
-  find.sync('.env') ||
-  find.sync('.env.local') ||
-  path.resolve(__dirname, '..', '.env.local');
+const { NODE_ENV, INIT_CWD: projectRoot } = process.env;
 
-require('dotenv').config({ path: envFile });
+const dotenvFiles = [
+  path.resolve(__dirname, '..', '.env.local'),
+  path.join(projectRoot, `.env.${NODE_ENV}.local`),
+  path.join(projectRoot, `.env.${NODE_ENV}`),
+  NODE_ENV !== 'test' && path.join(projectRoot, `.env.local`),
+  path.join(projectRoot, `.env`),
+].filter(Boolean);
+
+// Load environment variables from .env* files.
+// Use local .env as defaults
+dotenvFiles.forEach(dotenvFile => {
+  if (fs.existsSync(dotenvFile)) {
+    expand(
+      dotenv.config({
+        path: dotenvFile,
+      })
+    );
+  }
+});