From 2d8fdf30457021c287a23c19fc5bb48eb8f46a67 Mon Sep 17 00:00:00 2001
From: Adam Miller <adam@pages.me>
Date: Sun, 4 Sep 2016 20:59:52 -0700
Subject: [PATCH] Allow native Symbols as computed property names (#6705)

The for-in loop in helpers.defineEnumerableProperties doesn't iterate over Symbols.
If Object.getOwnPropertySymbols exists, include the discovered values when defining properties.
---
 packages/babel-helpers/src/helpers.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index b4b8c203a2..24e796a48c 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -278,6 +278,20 @@ helpers.defineEnumerableProperties = template(`
       if ("value" in desc) desc.writable = true;
       Object.defineProperty(obj, key, desc);
     }
+
+    // Symbols are not enumerated over by for-in loops. If native
+    // Symbols are available, fetch all of the descs object's own
+    // symbol properties and define them on our target object too.
+    if (Object.getOwnPropertySymbols) {
+      var objectSymbols = Object.getOwnPropertySymbols(descs);
+      for (var idx in objectSymbols) {
+        var sym = objectSymbols[idx];
+        var desc = descs[sym];
+        desc.configurable = desc.enumerable = true;
+        if ("value" in desc) desc.writable = true;
+        Object.defineProperty(obj, sym, desc);
+      }
+    }
     return obj;
   })
 `);