From 4730526bf26d7609cda4cfc0d158000cb420a846 Mon Sep 17 00:00:00 2001
From: Chris Cowan <agentme49@gmail.com>
Date: Mon, 18 Jan 2016 19:05:39 -0800
Subject: [PATCH 1/3] Add transform-es2015-duplicate-keys plugin.

---
 .../.npmignore                                |  3 ++
 .../README.md                                 | 40 +++++++++++++++++++
 .../package.json                              | 18 +++++++++
 .../src/index.js                              | 33 +++++++++++++++
 .../test/fixtures/combination/dupes/actual.js |  1 +
 .../fixtures/combination/dupes/expected.js    |  1 +
 .../fixtures/combination/no-dupes/actual.js   |  1 +
 .../fixtures/combination/no-dupes/expected.js |  1 +
 .../test/fixtures/combination/options.json    |  3 ++
 .../duplicate-keys/both-quoted/actual.js      |  1 +
 .../duplicate-keys/both-quoted/expected.js    |  1 +
 .../fixtures/duplicate-keys/dupes/actual.js   |  1 +
 .../fixtures/duplicate-keys/dupes/expected.js |  1 +
 .../fixtures/duplicate-keys/getter/actual.js  |  1 +
 .../duplicate-keys/getter/expected.js         |  3 ++
 .../duplicate-keys/no-dupes/actual.js         |  1 +
 .../duplicate-keys/no-dupes/expected.js       |  1 +
 .../duplicate-keys/one-quoted/actual.js       |  1 +
 .../duplicate-keys/one-quoted/expected.js     |  1 +
 .../test/fixtures/duplicate-keys/options.json |  3 ++
 .../test/index.js                             |  1 +
 21 files changed, 117 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/.npmignore
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/README.md
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/package.json
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/options.json
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/options.json
 create mode 100644 packages/babel-plugin-transform-es2015-duplicate-keys/test/index.js

diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/.npmignore b/packages/babel-plugin-transform-es2015-duplicate-keys/.npmignore
new file mode 100644
index 0000000000..246c4aa256
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/.npmignore
@@ -0,0 +1,3 @@
+node_modules
+src
+test
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/README.md b/packages/babel-plugin-transform-es2015-duplicate-keys/README.md
new file mode 100644
index 0000000000..0e5c9e8962
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/README.md
@@ -0,0 +1,40 @@
+# babel-plugin-transform-es2015-duplicate-keys
+
+Compile objects with duplicate keys to valid strict ES5.
+
+This plugin actually converts duplicate keys in objects to be computed
+properties, which then must be handled by the
+transform-es2015-computed-properties plugin. The final result won't contain any
+object literals with duplicate keys.
+
+## Installation
+
+```sh
+$ npm install babel-plugin-transform-es2015-duplicate-keys
+```
+
+## Usage
+
+### Via `.babelrc` (Recommended)
+
+**.babelrc**
+
+```json
+{
+  "plugins": ["transform-es2015-duplicate-keys"]
+}
+```
+
+### Via CLI
+
+```sh
+$ babel --plugins transform-es2015-duplicate-keys script.js
+```
+
+### Via Node API
+
+```javascript
+require("babel-core").transform("code", {
+  plugins: ["transform-es2015-duplicate-keys"]
+});
+```
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/package.json b/packages/babel-plugin-transform-es2015-duplicate-keys/package.json
new file mode 100644
index 0000000000..30efda522c
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/package.json
@@ -0,0 +1,18 @@
+{
+  "name": "babel-plugin-transform-es2015-duplicate-keys",
+  "version": "6.4.0",
+  "description": "Compile objects with duplicate keys to valid strict ES5",
+  "repository": "https://github.com/babel/babel/tree/master/packages/babel-plugin-transform-es2015-duplicate-keys",
+  "license": "MIT",
+  "main": "lib/index.js",
+  "keywords": [
+    "babel-plugin"
+  ],
+  "dependencies": {
+    "babel-runtime": "^5.0.0",
+    "babel-types": "^6.4.0"
+  },
+  "devDependencies": {
+    "babel-helper-plugin-test-runner": "^6.3.13"
+  }
+}
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js b/packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js
new file mode 100644
index 0000000000..7bfc68a785
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js
@@ -0,0 +1,33 @@
+import * as t from "babel-types";
+
+function getName(key) {
+  if (t.isIdentifier(key)) {
+    return key.name;
+  }
+  return key.value.toString();
+}
+
+export default function() {
+  return {
+    visitor: {
+      ObjectExpression(path) {
+        const { node } = path;
+        const plainProps = node.properties.filter(prop => !t.isSpreadProperty(prop) && !prop.computed);
+
+        const alreadySeenNames = Object.create(null);
+
+        for (let prop of plainProps) {
+          const name = getName(prop.key);
+          if (!alreadySeenNames[name]) {
+            alreadySeenNames[name] = true;
+          } else {
+            // Rely on the computed properties transform to split the property
+            // assignment out of the object literal.
+            prop.computed = true;
+            prop.key = t.stringLiteral(name);
+          }
+        }
+      }
+    }
+  };
+}
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/actual.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/actual.js
new file mode 100644
index 0000000000..cec58665c7
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/actual.js
@@ -0,0 +1 @@
+var x = { a: 5, a: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/expected.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/expected.js
new file mode 100644
index 0000000000..54c948c8e5
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/dupes/expected.js
@@ -0,0 +1 @@
+var x = babelHelpers.defineProperty({ a: 5 }, "a", 6);
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/actual.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/actual.js
new file mode 100644
index 0000000000..66138dc6b1
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/actual.js
@@ -0,0 +1 @@
+var x = { a: 5, b: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/expected.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/expected.js
new file mode 100644
index 0000000000..66138dc6b1
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/no-dupes/expected.js
@@ -0,0 +1 @@
+var x = { a: 5, b: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/options.json b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/options.json
new file mode 100644
index 0000000000..9ca5c26b5e
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/combination/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["external-helpers", "transform-es2015-duplicate-keys", "transform-es2015-computed-properties"]
+}
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/actual.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/actual.js
new file mode 100644
index 0000000000..3cd7f70f71
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/actual.js
@@ -0,0 +1 @@
+var x = { "a\n b": 5, "a\n b": 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/expected.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/expected.js
new file mode 100644
index 0000000000..485e0ceafc
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/both-quoted/expected.js
@@ -0,0 +1 @@
+var x = { "a\n b": 5, ["a\n b"]: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/actual.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/actual.js
new file mode 100644
index 0000000000..cec58665c7
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/actual.js
@@ -0,0 +1 @@
+var x = { a: 5, a: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/expected.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/expected.js
new file mode 100644
index 0000000000..b7d37c4511
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/dupes/expected.js
@@ -0,0 +1 @@
+var x = { a: 5, ["a"]: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/actual.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/actual.js
new file mode 100644
index 0000000000..abd4f63845
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/actual.js
@@ -0,0 +1 @@
+var x = { a: 5, get a() {return 6;} };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/expected.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/expected.js
new file mode 100644
index 0000000000..7b43d87415
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/getter/expected.js
@@ -0,0 +1,3 @@
+var x = { a: 5, get ["a"]() {
+    return 6;
+  } };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/actual.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/actual.js
new file mode 100644
index 0000000000..66138dc6b1
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/actual.js
@@ -0,0 +1 @@
+var x = { a: 5, b: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/expected.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/expected.js
new file mode 100644
index 0000000000..66138dc6b1
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/no-dupes/expected.js
@@ -0,0 +1 @@
+var x = { a: 5, b: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/actual.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/actual.js
new file mode 100644
index 0000000000..677b1ed40e
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/actual.js
@@ -0,0 +1 @@
+var x = { a: 5, "a": 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/expected.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/expected.js
new file mode 100644
index 0000000000..b7d37c4511
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/one-quoted/expected.js
@@ -0,0 +1 @@
+var x = { a: 5, ["a"]: 6 };
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/options.json b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/options.json
new file mode 100644
index 0000000000..a081c68256
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/fixtures/duplicate-keys/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-es2015-duplicate-keys"]
+}
diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/test/index.js b/packages/babel-plugin-transform-es2015-duplicate-keys/test/index.js
new file mode 100644
index 0000000000..1f6634aabd
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/test/index.js
@@ -0,0 +1 @@
+require("babel-helper-plugin-test-runner")(__dirname);

From f01eaa8e475da669881b1d267eaad52144c7d3f9 Mon Sep 17 00:00:00 2001
From: Chris Cowan <agentme49@gmail.com>
Date: Mon, 18 Jan 2016 19:06:00 -0800
Subject: [PATCH 2/3] Put transform-es2015-duplicate-keys plugin in es2015
 preset.

---
 packages/babel-preset-es2015/index.js     | 1 +
 packages/babel-preset-es2015/package.json | 1 +
 2 files changed, 2 insertions(+)

diff --git a/packages/babel-preset-es2015/index.js b/packages/babel-preset-es2015/index.js
index f8fdb617e4..d9b84f65d1 100644
--- a/packages/babel-preset-es2015/index.js
+++ b/packages/babel-preset-es2015/index.js
@@ -8,6 +8,7 @@ module.exports = {
     require("babel-plugin-transform-es2015-classes"),
     require("babel-plugin-transform-es2015-object-super"),
     require("babel-plugin-transform-es2015-shorthand-properties"),
+    require("babel-plugin-transform-es2015-duplicate-keys"),
     require("babel-plugin-transform-es2015-computed-properties"),
     require("babel-plugin-transform-es2015-for-of"),
     require("babel-plugin-transform-es2015-sticky-regex"),
diff --git a/packages/babel-preset-es2015/package.json b/packages/babel-preset-es2015/package.json
index 3abbd0bfce..5a8c0a0be5 100644
--- a/packages/babel-preset-es2015/package.json
+++ b/packages/babel-preset-es2015/package.json
@@ -17,6 +17,7 @@
     "babel-plugin-transform-es2015-object-super": "^6.3.13",
     "babel-plugin-transform-es2015-shorthand-properties": "^6.3.13",
     "babel-plugin-transform-es2015-computed-properties": "^6.3.13",
+    "babel-plugin-transform-es2015-duplicate-keys": "^6.4.0",
     "babel-plugin-transform-es2015-for-of": "^6.3.13",
     "babel-plugin-transform-es2015-sticky-regex": "^6.3.13",
     "babel-plugin-transform-es2015-unicode-regex": "^6.3.13",

From b2aecd4320d131d6cb5ee086804042a21335962f Mon Sep 17 00:00:00 2001
From: Chris Cowan <agentme49@gmail.com>
Date: Fri, 26 Feb 2016 08:57:34 -0800
Subject: [PATCH 3/3] Fix arrow style issue

---
 .../babel-plugin-transform-es2015-duplicate-keys/src/index.js   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js b/packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js
index 7bfc68a785..be9fab7851 100644
--- a/packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js
+++ b/packages/babel-plugin-transform-es2015-duplicate-keys/src/index.js
@@ -12,7 +12,7 @@ export default function() {
     visitor: {
       ObjectExpression(path) {
         const { node } = path;
-        const plainProps = node.properties.filter(prop => !t.isSpreadProperty(prop) && !prop.computed);
+        const plainProps = node.properties.filter((prop) => !t.isSpreadProperty(prop) && !prop.computed);
 
         const alreadySeenNames = Object.create(null);