Add _.chunk to Array functions.

test/arrays.js

@@ -376,5 +376,18 @@
     deepEqual(_.range(12, 7, -2), [12, 10, 8], 'range with three arguments a & b & c, a > b, c < 0 generates an array of elements a,a-c,a-2c and ends with the number not less than b');
     deepEqual(_.range(0, -10, -1), [0, -1, -2, -3, -4, -5, -6, -7, -8, -9], 'final example in the Python docs');
   });
-
+
+  test('chunk', function() {
+    deepEqual(_.chunk([], 2), [], 'chunk for empty array returns an empty array');
+
+    deepEqual(_.chunk([1, 2, 3], 0), [], 'chunk into parts of 0 elements returns an empty array');
+    deepEqual(_.chunk([1, 2, 3], -1), [], 'chunk into parts of negative amount of elements returns an empty array');
+
+    deepEqual(_.chunk([1, 2, 3], 3), [1, 2, 3], 'chunk into parts of current array length elements returns the original array');
+    deepEqual(_.chunk([1, 2, 3], 5), [1, 2, 3], 'chunk into parts of more then current array length elements returns the original array');
+
+    deepEqual(_.chunk([10, 20, 30, 40, 50, 60, 70], 2), [[10, 20], [30, 40], [50, 60], [70]], 'chunk into parts of less then current array length elements');
+    deepEqual(_.chunk([10, 20, 30, 40, 50, 60, 70], 3), [[10, 20, 30], [40, 50, 60], [70]], 'chunk into parts of less then current array length elements');
+  });
+
 }());

underscore.js

@@ -635,6 +635,19 @@
 
     return range;
   };
+
+  // Split an **array** into several arrays containing **int** or less elements
+  // of initial array
+  _.chunk = function(array, int) {
+    var result = [];
+
+    if (int <= 0) return [];
+    if (int >= _.size(array)) return array;
+
+    while (_.size(array) > 0) result.push(array.splice(0, int));
+
+    return result;
+  };
 
   // Function (ahem) Functions
   // ------------------