[RFC] Use rollup to build the code and generate CommonJS and UMD version

.gitignore

@@ -1,5 +1,6 @@
 coverage/
 node_modules/
+tmp/
 .nyc_output/
 npm-debug.log
 package-lock.json

bin/build.js

@@ -33,18 +33,16 @@ var build = () => {
     'utf8'
   )
 
-  // update slugify
-  var source =
-    fs.readFileSync(path.resolve(__dirname, '../slugify.js'), 'utf8')
-      .replace(
-        /var charMap = JSON\.parse\(.*\)/,
-        `var charMap = JSON.parse('${JSON.stringify(sort(charmap)).replace(/'/g, '\\\'')}')`
-      )
-      .replace(
-        /var locales = JSON\.parse\(.*\)/,
-        `var locales = JSON.parse('${JSON.stringify(clean(locales))}')`
-      )
-  fs.writeFileSync(path.resolve(__dirname, '../slugify.js'), source, 'utf8')
+  // update locales.json in tmp folder
+  var tmpDir = path.resolve(__dirname, '../tmp');
+  if (!fs.existsSync(tmpDir)) {
+    fs.mkdirSync(tmpDir);
+  }
+  fs.writeFileSync(
+    path.resolve(tmpDir, 'locales.json'),
+    JSON.stringify(clean(locales), null, 2),
+    'utf8'
+  )
 }
 
 build()

package.json

@@ -19,18 +19,25 @@
     "coveralls": "^3.1.0",
     "github-changes": "^2.0.3",
     "mocha": "^7.2.0",
-    "nyc": "^15.1.0"
+    "nyc": "^15.1.0",
+    "rollup": "^1.32.1",
+    "@rollup/plugin-json": "^4.1.0"
   },
-  "main": "./slugify.js",
+  "main": "./slugify.cjs.js",
+  "module": "./slugify.mjs",
+  "unpkg": "./slugify.js",
+  "jsdelivr": "./slugify.js",
   "files": [
     "LICENSE",
     "README.md",
     "slugify.d.ts",
+    "slugify.cjs.js",
+    "slugify.mjs",
     "slugify.js"
   ],
   "types": "slugify.d.ts",
   "scripts": {
-    "build": "node bin/build",
+    "build": "node bin/build && npx rollup -c",
     "build:changelog": "github-changes --owner simov --repository slugify --only-pulls --use-commit-body --date-format '(YYYY-MM-DD)' --file CHANGELOG.md --verbose",
     "test:ci": "npx mocha --recursive",
     "test:cov": "npx nyc --reporter=lcov --reporter=text-summary mocha -- --recursive",

rollup.config.js

@@ -0,0 +1,19 @@
+import pkg from './package.json';
+import json from '@rollup/plugin-json';
+
+export default [
+  {
+   input: 'src/slugify.js',
+   output: [
+      { file: pkg.main, format: 'cjs', exports: 'auto' },
+      { file: pkg.module, format: 'esm', exports: 'auto' },
+      { file: pkg.unpkg, format: 'umd', exports: 'auto', name: 'slugify' }
+   ],
+   plugins: [
+     json({
+       compact: true,
+       namedExports: false
+     })
+   ]
+ }
+];