Add UMD bundles (#1178)

They are useful to use in browser and at least now we may see how big
this lib is.

.babelrc

@@ -1,3 +1,10 @@
 {
-  "presets": ["jason"]
+  "presets": ["jason"],
+  "env": {
+    "esm": {
+      "presets": [
+        ["jason", { "modules": false }]
+      ]
+    }
+  }
 }

.gitignore

@@ -1,4 +1,5 @@
 lib/
+dist/
 
 # Logs
 logs
@@ -32,4 +33,4 @@ node_modules
 .idea
 
 # Mac OS X
-.DS_Store
+.DS_Store

.size-snapshot.json

@@ -0,0 +1,12 @@
+{
+  "./dist/react-big-calendar.js": {
+    "bundled": 470107,
+    "minified": 152579,
+    "gzipped": 42233
+  },
+  "./dist/react-big-calendar.min.js": {
+    "bundled": 439313,
+    "minified": 142681,
+    "gzipped": 39554
+  }
+}

package.json

@@ -9,6 +9,7 @@
   "style": "lib/css/react-big-calendar.css",
   "files": [
     "lib/",
+    "dist/",
     "LICENSE",
     "README.md",
     "CHANGELOG.md"
@@ -29,7 +30,9 @@
     "less-dnd": "npm run l src/addons/dragAndDrop/styles.less ./lib/addons/dragAndDrop/styles.css",
     "assets": "cpy src/less/* lib/less && npm run assets-addons",
     "assets-addons": "cpy addons/**/*.less ../lib/ --cwd=src --parents",
-    "build": "npm run clean && babel src --out-dir lib && npm run assets && npm run less",
+    "build:umd": "BABEL_ENV=esm yarn rollup -c",
+    "build:cjs": "babel src --out-dir lib",
+    "build": "yarn clean && yarn build:cjs && yarn build:umd && yarn assets && yarn less",
     "build:examples": "npm run clean:examples && webpack --config examples/webpack.config.js",
     "examples": "npm run clean:examples && webpack-dev-server --config examples/webpack.config.js --mode development",
     "lint": "eslint src test",
@@ -97,6 +100,13 @@
     "react-dom": "^16.6.1",
     "react-tackle-box": "^2.1.0",
     "rimraf": "^2.4.2",
+    "rollup": "^1.1.0",
+    "rollup-plugin-babel": "^4.3.0",
+    "rollup-plugin-commonjs": "^9.2.0",
+    "rollup-plugin-node-resolve": "^4.0.0",
+    "rollup-plugin-replace": "^2.1.0",
+    "rollup-plugin-size-snapshot": "^0.8.0",
+    "rollup-plugin-terser": "^4.0.2",
     "webpack": "^4.25.1",
     "webpack-atoms": "^8.0.0",
     "webpack-cli": "^3.1.2",

rollup.config.js

@@ -0,0 +1,61 @@
+import nodeResolve from 'rollup-plugin-node-resolve'
+import babel from 'rollup-plugin-babel'
+import commonjs from 'rollup-plugin-commonjs'
+import replace from 'rollup-plugin-replace'
+import { sizeSnapshot } from 'rollup-plugin-size-snapshot'
+import { terser } from 'rollup-plugin-terser'
+
+const input = './src/index.js'
+const name = 'ReactBigCalendar'
+const globals = {
+  react: 'React',
+  'react-dom': 'ReactDOM',
+}
+
+const babelOptions = {
+  exclude: /node_modules/,
+  runtimeHelpers: true,
+}
+
+const commonjsOptions = {
+  include: /node_modules/,
+}
+
+export default [
+  {
+    input,
+    output: {
+      file: './dist/react-big-calendar.js',
+      format: 'umd',
+      name,
+      globals,
+    },
+    external: Object.keys(globals),
+    plugins: [
+      nodeResolve(),
+      babel(babelOptions),
+      commonjs(commonjsOptions),
+      replace({ 'process.env.NODE_ENV': JSON.stringify('development') }),
+      sizeSnapshot(),
+    ],
+  },
+
+  {
+    input,
+    output: {
+      file: './dist/react-big-calendar.min.js',
+      format: 'umd',
+      name,
+      globals,
+    },
+    external: Object.keys(globals),
+    plugins: [
+      nodeResolve(),
+      babel(babelOptions),
+      commonjs(commonjsOptions),
+      replace({ 'process.env.NODE_ENV': JSON.stringify('production') }),
+      sizeSnapshot(),
+      terser(),
+    ],
+  },
+]