Fix breakages caused by switch to fbjs

Summary: This fixes a couple of breakages introduced by the switch to fbjs

Reviewed By: bestander

Differential Revision: D3000078

fb-gh-sync-id: 2971d049030f754d5001f6729716373a64078ddf
shipit-source-id: 2971d049030f754d5001f6729716373a64078ddf

Libraries/vendor/core/isEmpty.js

@@ -0,0 +1,34 @@
+/**
+ * @generated SignedSource<<97ffcebc9ae390e734026a4f3964bff6>>
+ *
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ * !! This file is a check-in of a static_upstream project!      !!
+ * !!                                                            !!
+ * !! You should not modify this file directly. Instead:         !!
+ * !! 1) Use `fjs use-upstream` to temporarily replace this with !!
+ * !!    the latest version from upstream.                       !!
+ * !! 2) Make your changes, test them, etc.                      !!
+ * !! 3) Use `fjs push-upstream` to copy your changes back to    !!
+ * !!    static_upstream.                                        !!
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ *
+ * @providesModule isEmpty
+ */
+
+/**
+ * Mimics empty from PHP.
+ */
+function isEmpty(obj) {
+  if (Array.isArray(obj)) {
+    return obj.length === 0;
+  } else if (typeof obj === 'object') {
+    for (var i in obj) {
+      return false;
+    }
+    return true;
+  } else {
+    return !obj;
+  }
+}
+
+module.exports = isEmpty;