.uglifyrc config support (#287)

* run prettier

* add uglify config

src/transforms/uglify.js

@@ -1,11 +1,17 @@
 const {minify} = require('uglify-es');
+const config = require('../utils/config');
+
+async function getConfig(asset) {
+  return config.load(asset.name, ['.uglifyrc']);
+}
 
 module.exports = async function(asset) {
   await asset.parseIfNeeded();
 
   // Convert AST into JS
   let code = asset.generate().js;
 
+  let customConfig = await getConfig(asset);
   let options = {
     warnings: true,
     mangle: {
@@ -16,6 +22,10 @@ module.exports = async function(asset) {
     }
   };
 
+  if (customConfig) {
+    options = Object.assign(options, customConfig);
+  }
+
   let result = minify(code, options);
 
   if (result.error) throw result.error;

test/integration/uglify-config/.uglifyrc

@@ -0,0 +1,5 @@
+{
+  "compress": {
+    "drop_console": false
+  }
+}

test/integration/uglify-config/index.js

@@ -0,0 +1,4 @@
+module.exports = function () {
+    console.log('Hello world');
+    return 1 + 1;
+};

test/javascript.js

@@ -175,6 +175,19 @@ describe('javascript', function() {
     assert(!js.includes('local.a'));
   });
 
+  it('should use uglify config', async function() {
+    let b = await bundle(__dirname + '/integration/uglify-config/index.js', {
+      production: true
+    });
+
+    let output = run(b);
+    assert.equal(typeof output, 'function');
+    assert.equal(output(), 2);
+
+    let js = fs.readFileSync(__dirname + '/dist/index.js', 'utf8');
+    assert(js.includes('console.log'));
+  });
+
   it('should insert global variables when needed', async function() {
     let b = await bundle(__dirname + '/integration/globals/index.js');