Merge pull request #17537 from bekzod/dont-alloc-array

don't allocate array when object empty in ObjectIterator
emberjs · Jan 31, 2019 · b2aa84a · b2aa84a
2 parents 7df81ec + 85b9324
commit b2aa84a
Showing 1 changed file with 4 additions and 6 deletions.
diff --git a/packages/@ember/-internals/glimmer/lib/utils/iterable.ts b/packages/@ember/-internals/glimmer/lib/utils/iterable.ts
@@ -120,17 +120,15 @@ class EmberArrayIterator extends BoundedIterator {
 class ObjectIterator extends BoundedIterator {
   static fromIndexable(obj: Indexable, keyFor: KeyFor): OpaqueIterator {
     let keys = Object.keys(obj);
-    let values: Opaque[] = [];
-
     let { length } = keys;
 
-    for (let i = 0; i < length; i++) {
-      values.push(get(obj, keys[i]));
-    }
-
     if (length === 0) {
       return EMPTY_ITERATOR;
     } else {
+      let values: Opaque[] = [];
+      for (let i = 0; i < length; i++) {
+        values.push(get(obj, keys[i]));
+      }
       return new this(keys, values, length, keyFor);
     }
   }