Merge pull request #475 from Daveloper87/empty_handle_undefined

Added handling for undefined and null on expect empty (fails on negate flag too)

lib/chai/core/assertions.js

@@ -373,17 +373,10 @@ module.exports = function (chai, _) {
    */
 
   Assertion.addProperty('empty', function () {
-    var obj = flag(this, 'object')
-      , expected = obj;
-
-    if (Array.isArray(obj) || 'string' === typeof object) {
-      expected = obj.length;
-    } else if (typeof obj === 'object') {
-      expected = Object.keys(obj).length;
-    }
-
+    var obj = flag(this, 'object');
+    new Assertion(obj).to.exist;
     this.assert(
-        !expected
+        Object.keys(Object(obj)).length === 0
       , 'expected #{this} to be empty'
       , 'expected #{this} not to be empty'
     );

test/expect.js

@@ -397,6 +397,31 @@ describe('expect', function () {
     err(function(){
       expect({foo: 'bar'}).to.be.empty;
     }, "expected { foo: \'bar\' } to be empty");
+
+    err(function(){
+      expect(null).to.be.empty;
+    }, "expected null to exist");
+
+    err(function(){
+      expect(undefined).to.be.empty;
+    }, "expected undefined to exist");
+
+    err(function(){
+      expect().to.be.empty;
+    }, "expected undefined to exist");
+
+    err(function(){
+      expect(null).to.not.be.empty;
+    }, "expected null to exist");
+
+    err(function(){
+      expect(undefined).to.not.be.empty;
+    }, "expected undefined to exist");
+
+    err(function(){
+      expect().to.not.be.empty;
+    }, "expected undefined to exist");
+
   });
 
   it('property(name)', function(){