Allow null or undefined elements in _.pluck, _.property, and _.invoke.

lodash.js

@@ -4023,7 +4023,8 @@
           result = Array(length < 0 ? 0 : length >>> 0);
 
       baseEach(collection, function(value) {
-        result[++index] = (isFunc ? methodName : value[methodName]).apply(value, args);
+        var func = isFunc ? methodName : (value != null && value[methodName]);
+        result[++index] = func ? func.apply(value, args) : undefined;
       });
       return result;
     }
@@ -7904,7 +7905,7 @@
      */
     function property(key) {
       return function(object) {
-        return object[key];
+        return object == null ? undefined : object[key];
       };
     }
 

test/test.js

@@ -3636,8 +3636,8 @@
 
   (function() {
     test('should invoke a methods on each element of a collection', 1, function() {
-      var actual = _.invoke(['a', 'b', 'c'], 'toUpperCase');
-      deepEqual(actual, ['A', 'B', 'C']);
+      var array = ['a', 'b', 'c'];
+      deepEqual( _.invoke(array, 'toUpperCase'), ['A', 'B', 'C']);
     });
 
     test('should work with a function `methodName` argument', 1, function() {
@@ -3652,6 +3652,11 @@
       var object = { 'a': 1, 'b': 2, 'c': 3 };
       deepEqual(_.invoke(object, 'toFixed', 1), ['1.0', '2.0', '3.0']);
     });
+
+    test('should work with `null` or `undefined` elements', 1, function() {
+      var array = ['a', null, undefined, 'd'];
+      deepEqual(_.invoke(array, 'toUpperCase'), ['A', undefined, undefined, 'D']);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -6480,6 +6485,11 @@
       var object = { 'a': [1], 'b': [1, 2], 'c': [1, 2, 3] };
       deepEqual(_.pluck(object, 'length'), [1, 2, 3]);
     });
+
+    test('should work with `null` or `undefined` elements', 1, function() {
+      var objects = [{ 'a': 1 }, null, undefined, { 'a': 4 }];
+      deepEqual(_.pluck(objects, 'a'), [1, undefined, undefined, 4]);
+    });
   }());
 
   /*--------------------------------------------------------------------------*/