Minify prelude.js (parcel-bundler#431)

* run prettier

* minify

* fix linting issues

.eslintignore

@@ -16,5 +16,6 @@ lib
 dist
 /test/dist
 /test/input
+minified
 
 coverage

.gitignore

@@ -11,3 +11,4 @@ lib
 !test/**/node_modules
 .vscode/
 .idea/
+minified/

minify.js

@@ -0,0 +1,41 @@
+const uglify = require('uglify-es');
+const fs = require('./src/utils/fs');
+const path = require('path');
+
+async function minify(inputPath, outputPath) {
+  let input = (await fs.readFile(inputPath)).toString();
+
+  // Minify input
+  let options = {
+    mangle: {
+      toplevel: true
+    },
+    output: {
+      ecma: 3,
+      semicolons: false
+    }
+  };
+  let res = uglify.minify(input, options);
+
+  // Write output
+  await fs.mkdirp(path.dirname(outputPath));
+  await fs.writeFile(outputPath, res.code);
+}
+
+async function runMinifier() {
+  let files = ['prelude.js'];
+
+  files.forEach(async file => {
+    await minify(
+      path.join('./src/builtins/', file),
+      path.join('./minified/builtins/', file)
+    );
+    // eslint-disable-next-line no-console
+    console.log('minified: ' + file);
+    return;
+  });
+}
+
+(async () => {
+  await runMinifier();
+})();

packages/core/parcel-bundler/package.json

@@ -70,7 +70,8 @@
     "test": "cross-env NODE_ENV=test mocha",
     "format": "prettier --write './{src,bin,test}/**/*.{js,json,md}'",
     "build": "babel src -d lib",
-    "prepublish": "yarn build",
+    "prepublish": "yarn build && npm run minify",
+    "minify": "node ./minify.js",
     "precommit": "npm run lint && lint-staged",
     "lint": "eslint .",
     "postinstall":

packages/core/parcel-bundler/src/builtins/prelude.js

@@ -6,6 +6,7 @@
 // anything defined in a previous bundle is accessed via the
 // orig method which is the require for previous bundles
 
+// eslint-disable-next-line no-global-assign
 require = (function (modules, cache, entry) {
   // Save the require from previous bundle to this closure if any
   var previousRequire = typeof require === "function" && require;

packages/core/parcel-bundler/src/packagers/JSPackager.js

@@ -1,20 +1,30 @@
 const fs = require('fs');
-const {basename} = require('path');
+const path = require('path');
 const Packager = require('./Packager');
 
-const prelude = fs
-  .readFileSync(__dirname + '/../builtins/prelude.js', 'utf8')
-  .trim();
+const prelude = {
+  source: fs
+    .readFileSync(path.join(__dirname, '../builtins/prelude.js'), 'utf8')
+    .trim(),
+  minified: fs
+    .readFileSync(
+      path.join(__dirname, '../../minified/builtins/prelude.js'),
+      'utf8'
+    )
+    .trim()
+};
+
 const hmr = fs
-  .readFileSync(__dirname + '/../builtins/hmr-runtime.js', 'utf8')
+  .readFileSync(path.join(__dirname, '../builtins/hmr-runtime.js'), 'utf8')
   .trim();
 
 class JSPackager extends Packager {
   async start() {
     this.first = true;
     this.dedupe = new Map();
 
-    await this.dest.write(prelude + '({');
+    let preludeCode = this.options.minify ? prelude.minified : prelude.source;
+    await this.dest.write(preludeCode + '({');
   }
 
   async addAsset(asset) {
@@ -33,10 +43,10 @@ class JSPackager extends Packager {
 
       // For dynamic dependencies, list the child bundles to load along with the module id
       if (dep.dynamic && this.bundle.childBundles.has(mod.parentBundle)) {
-        let bundles = [basename(mod.parentBundle.name)];
+        let bundles = [path.basename(mod.parentBundle.name)];
         for (let child of mod.parentBundle.siblingBundles.values()) {
           if (!child.isEmpty) {
-            bundles.push(basename(child.name));
+            bundles.push(path.basename(child.name));
           }
         }