Fixed shallowEqual implementation to handle the case when inputs are …

…not objects.

If either argument is not an object and unequal, then shallowEqual should return false.
If only one argument is an object, then shallowEqual should return false.

Fixes facebook#3369

src/utils/__tests__/shallowEqual-test.js

@@ -41,6 +41,24 @@ describe('shallowEqual', function() {
     ).toBe(true);
   });
 
+  it('returns false if arguments are not objects and not equal', function() {
+    expect(
+      shallowEqual(
+        1,
+        2
+      )
+    ).toBe(false);
+  });
+
+  it('returns false if only one argument is not an object', function() {
+    expect(
+      shallowEqual(
+        1,
+        {}
+      )
+    ).toBe(false);
+  })
+
   it('returns false if first argument has too many keys', function() {
     expect(
       shallowEqual(

src/utils/shallowEqual.js

@@ -27,6 +27,10 @@ function shallowEqual(objA, objB) {
     return false;
   }
 
+  if (typeof objA !== 'object' || typeof objB !== 'object') {
+    return false;
+  }
+
   var key;
   // Test for A's keys different from B.
   for (key in objA) {