Allow partial validation when using validate decorator (#296)

voluptuous/schema_builder.py

@@ -1171,7 +1171,8 @@ def validate_schema_decorator(func):
             returns = schema_arguments[RETURNS_KEY]
             del schema_arguments[RETURNS_KEY]
 
-        input_schema = Schema(schema_arguments) if len(schema_arguments) != 0 else lambda x: x
+        input_schema = (Schema(schema_arguments, extra=ALLOW_EXTRA)
+                        if len(schema_arguments) != 0 else lambda x: x)
         output_schema = Schema(returns) if returns_defined else lambda x: x
 
         @wraps(func)

voluptuous/tests/tests.py

@@ -680,6 +680,38 @@ def fn(arg):
     assert_raises(Invalid, fn, 1)
 
 
+def test_schema_decorator_partial_match_called_with_args():
+    @validate(arg1=int)
+    def fn(arg1, arg2):
+        return arg1
+
+    fn(1, "foo")
+
+
+def test_schema_decorator_partial_unmatch_called_with_args():
+    @validate(arg1=int)
+    def fn(arg1, arg2):
+        return arg1
+
+    assert_raises(Invalid, fn, "bar", "foo")
+
+
+def test_schema_decorator_partial_match_called_with_kwargs():
+    @validate(arg2=int)
+    def fn(arg1, arg2):
+        return arg1
+
+    fn(arg1="foo", arg2=1)
+
+
+def test_schema_decorator_partial_unmatch_called_with_kwargs():
+    @validate(arg2=int)
+    def fn(arg1, arg2):
+        return arg1
+
+    assert_raises(Invalid, fn, arg1=1, arg2="foo")
+
+
 def test_unicode_as_key():
     if sys.version_info >= (3,):
         text_type = str