From 95f5eb612cbbe687bfe0dffae3236ec156ea68a6 Mon Sep 17 00:00:00 2001
From: Erik Arvidsson <erik.arvidsson@gmail.com>
Date: Fri, 10 Aug 2018 19:44:57 -0700
Subject: [PATCH] Enable Object Rest Spread by default (#1835)

This uses Babel's plugin:
https://babeljs.io/docs/en/babel-plugin-transform-object-rest-spread

Spec:
https://tc39.github.io/ecma262/#sec-object-initializer-runtime-semantics-propertydefinitionevaluation

Fixes #1221, #1422
---
 packages/core/parcel/package.json               |  1 +
 packages/core/parcel/src/transforms/babel.js    |  8 ++++++++
 .../object-rest-spread/object-rest-spread.js    |  7 +++++++
 packages/core/parcel/test/javascript.js         | 17 +++++++++++++++++
 yarn.lock                                       | 11 +++++++++++
 5 files changed, 44 insertions(+)
 create mode 100644 packages/core/parcel/test/integration/object-rest-spread/object-rest-spread.js

diff --git a/packages/core/parcel/package.json b/packages/core/parcel/package.json
index fe02cf5cd76..bbda5fc5be3 100644
--- a/packages/core/parcel/package.json
+++ b/packages/core/parcel/package.json
@@ -20,6 +20,7 @@
     "babel-core": "^6.25.0",
     "babel-generator": "^6.25.0",
     "babel-plugin-transform-es2015-modules-commonjs": "^6.26.0",
+    "babel-plugin-transform-object-rest-spread": "^6.26.0",
     "babel-plugin-transform-react-jsx": "^6.24.1",
     "babel-preset-env": "^1.7.0",
     "babel-template": "^6.26.0",
diff --git a/packages/core/parcel/src/transforms/babel.js b/packages/core/parcel/src/transforms/babel.js
index 841d6a65ba9..4b14dfe6f27 100644
--- a/packages/core/parcel/src/transforms/babel.js
+++ b/packages/core/parcel/src/transforms/babel.js
@@ -265,6 +265,14 @@ async function getEnvPlugins(targets, useBuiltIns = false) {
     {},
     {targets, modules: false, useBuiltIns: useBuiltIns ? 'entry' : false}
   ).plugins;
+
+  // babel-preset-env version 6.x does not cover object-rest-spread so always
+  // add it.
+  plugins.push([
+    require('babel-plugin-transform-object-rest-spread'),
+    {useBuiltIns}
+  ]);
+
   envCache.set(key, plugins);
   return plugins;
 }
diff --git a/packages/core/parcel/test/integration/object-rest-spread/object-rest-spread.js b/packages/core/parcel/test/integration/object-rest-spread/object-rest-spread.js
new file mode 100644
index 00000000000..5a47ee9be8f
--- /dev/null
+++ b/packages/core/parcel/test/integration/object-rest-spread/object-rest-spread.js
@@ -0,0 +1,7 @@
+var x = {a: 'a', b: 'b'};
+var {a: y, ...ys} = x;
+var z = {y, ...ys};
+
+export default function () {
+  return {x, y, z, ys};
+}
diff --git a/packages/core/parcel/test/javascript.js b/packages/core/parcel/test/javascript.js
index 5a05db1b17b..e2a28891da5 100644
--- a/packages/core/parcel/test/javascript.js
+++ b/packages/core/parcel/test/javascript.js
@@ -28,6 +28,23 @@ describe('javascript', function() {
     assert.equal(output.default(), 3);
   });
 
+  it('should produce a basic JS bundle with object rest spread support', async function() {
+    let b = await bundle(
+      __dirname + '/integration/object-rest-spread/object-rest-spread.js'
+    );
+
+    assert.equal(b.assets.size, 1);
+
+    let output = await run(b);
+    assert.equal(typeof output, 'object');
+    assert.equal(typeof output.default, 'function');
+
+    let res = output.default();
+    assert.equal(res.y, 'a');
+    assert.deepEqual(res.z, {y: 'a', b: 'b'});
+    assert.deepEqual(res.ys, {b: 'b'});
+  });
+
   it('should bundle node_modules on --target=browser', async function() {
     let b = await bundle(__dirname + '/integration/node_require/main.js', {
       target: 'browser'
diff --git a/yarn.lock b/yarn.lock
index 21ec9283731..fa1b85b3f9a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -543,6 +543,10 @@ babel-plugin-syntax-jsx@^6.8.0:
   version "6.18.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-syntax-jsx/-/babel-plugin-syntax-jsx-6.18.0.tgz#0af32a9a6e13ca7a3fd5069e62d7b0f58d0d8946"
 
+babel-plugin-syntax-object-rest-spread@^6.8.0:
+  version "6.13.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-syntax-object-rest-spread/-/babel-plugin-syntax-object-rest-spread-6.13.0.tgz#fd6536f2bce13836ffa3a5458c4903a597bb3bf5"
+
 babel-plugin-syntax-trailing-function-commas@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-syntax-trailing-function-commas/-/babel-plugin-syntax-trailing-function-commas-6.22.0.tgz#ba0360937f8d06e40180a43fe0d5616fff532cf3"
@@ -737,6 +741,13 @@ babel-plugin-transform-exponentiation-operator@^6.22.0:
     babel-plugin-syntax-exponentiation-operator "^6.8.0"
     babel-runtime "^6.22.0"
 
+babel-plugin-transform-object-rest-spread@^6.26.0:
+  version "6.26.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-transform-object-rest-spread/-/babel-plugin-transform-object-rest-spread-6.26.0.tgz#0f36692d50fef6b7e2d4b3ac1478137a963b7b06"
+  dependencies:
+    babel-plugin-syntax-object-rest-spread "^6.8.0"
+    babel-runtime "^6.26.0"
+
 babel-plugin-transform-react-jsx@^6.24.1:
   version "6.24.1"
   resolved "https://registry.yarnpkg.com/babel-plugin-transform-react-jsx/-/babel-plugin-transform-react-jsx-6.24.1.tgz#840a028e7df460dfc3a2d29f0c0d91f6376e66a3"