Make it works for Array

index.js

@@ -44,6 +44,18 @@ function extend(target, obj) {
           target[key] = val;
         }
         target[key] = assign(target[key] || {}, val);
+      } else if (isArray(val)) {
+        var array = [];
+        for (var i = 0; i < val.length; i++) {
+          if (isPrimitive(val[i])) {
+            array.push(val[i]);
+          } else {
+            array.push(assign({}, val[i]));
+          }
+
+        }
+        target[key] = array;
+
       } else {
         target[key] = val;
       }
@@ -60,6 +72,13 @@ function isObject(obj) {
   return typeOf(obj) === 'object' || typeOf(obj) === 'function';
 }
 
+/**
+ * Returns true if the object is an array.
+ */
+function isArray(obj) {
+  return typeOf(obj) === 'array';
+}
+
 /**
  * Returns true if the given `key` is an own property of `obj`.
  */

test.js

@@ -130,7 +130,7 @@ describe('assign', function() {
     var two = {e: 'f', g: ['h']};
     assign(one, two);
     assert.deepEqual(one.g, ['h']);
-    assert.equal(one.g, two.g);
+    assert.deepEqual(one.g, two.g);
     assert.equal(typeof one, 'function');
   });
 
@@ -322,5 +322,28 @@ describe('symbols', function() {
       var res = assign(a, b);
       assert.equal(res[key], 'xyz');
     });
+
+    it('should deeply assign properties in an array:', function() {
+      var template = {
+        b: [
+          {
+
+            a: {
+              a: 0
+            }
+          }
+        ]
+      };
+      var one = assign({}, template);
+      var two = assign({}, template);
+      one.b[0].a = {
+        b: 0
+      };
+      two.b[0].a = {
+        c: 0
+      };
+
+      assert.deepEqual(one.b[0].a, {b: 0});
+    });
   }
 });