stripping comments

.babelrc

@@ -1,3 +1,4 @@
 {
-  "presets": ["flow"]
-}
+  "presets": ["flow", ["env", { "modules": false, "loose": true }]],
+  "comments": false
+}

.gitignore

@@ -11,12 +11,6 @@ node_modules/
 # generated files
 dist/
 
-# generated site
-site/
-
-# coverage reports
-coverage/
-
 # logs
 yarn-error.log
 npm-debug.log

package.json

@@ -5,20 +5,28 @@
   "main": "dist/react-beautiful-dnd.cjs.js",
   "module": "dist/react-beautiful-dnd.esm.js",
   "sideEffects": false,
-  "files": ["/dist", "/src"],
+  "files": [
+    "/dist",
+    "/src"
+  ],
   "author": "Alex Reardon <alexreardon@gmail.com>",
   "license": "MIT",
   "scripts": {
     "test": "yarn jest",
     "lint": "yarn prettier --debug-check src/** test/**",
     "typecheck": "yarn flow",
-    "validate": "yarn lint && yarn flow"
+    "validate": "yarn lint && yarn flow",
+    "build": "yarn rollup --config rollup.config.js"
   },
   "devDependencies": {
     "babel-cli": "^6.26.0",
+    "babel-core": "^6.26.0",
+    "babel-preset-env": "^1.6.1",
     "babel-preset-flow": "^6.23.0",
     "flow-bin": "^0.70.0",
     "jest": "^22.4.3",
-    "prettier": "^1.12.1"
+    "prettier": "^1.12.1",
+    "rollup": "^0.58.0",
+    "rollup-plugin-babel": "^3.0.3"
   }
 }

rollup.config.js

@@ -0,0 +1,29 @@
+import babel from 'rollup-plugin-babel';
+
+const input = 'src/index.js';
+
+const babelOptions = {
+  // only transpile our source code
+  exclude: 'node_modules/**',
+};
+
+export default [
+  // ESM build
+  {
+    input,
+    output: {
+      file: 'dist/tiny-invariant.esm.js',
+      format: 'es',
+    },
+    plugins: [babel()],
+  },
+  // CommonJS build
+  {
+    input,
+    output: {
+      file: 'dist/tiny-invariant.cjs.js',
+      format: 'cjs',
+    },
+    plugins: [babel()],
+  },
+];

src/index.js

@@ -5,7 +5,8 @@ const prefix: string = 'Invariant failed';
 
 // Throw an error if the condition fails
 // Strip out error messages for production
-export default (condition: mixed, message?: string = '') => {
+// > Not providing an inline default argument for message as the result is smaller
+export default (condition: mixed, message?: string) => {
   if (condition) {
     return;
   }
@@ -18,5 +19,5 @@ export default (condition: mixed, message?: string = '') => {
   }
 
   // In other environments we throw with the message
-  throw new Error(`${prefix}: ${message}`);
+  throw new Error(`${prefix}: ${message || ''}`);
 };