Add preserve_unknown to the Schema options

cliquet/schema.py

@@ -47,10 +47,13 @@ class Options:
         * ``readonly_fields``: Fields that cannot be updated
         * ``unique_fields``: Fields that must have unique values for the user
           collection.
+        * ``preserve_unknown``: Define if unknown fields should be preserved
+          or not (default False).
 
         """
         readonly_fields = ('id', 'last_modified')
         unique_fields = ('id', 'last_modified')
+        preserve_unknown = False
 
     def is_readonly(self, field):
         """Return True if specified field name is read-only.
@@ -62,3 +65,10 @@ def is_readonly(self, field):
         :rtype: boolean
         """
         return field in self.Options.readonly_fields
+
+    def schema_type(self, **kw):
+        if self.Options.preserve_unknown is True:
+            unknown = 'preserve'
+        else:
+            unknown = 'ignore'
+        return colander.Mapping(unknown=unknown)

cliquet/tests/test_schema.py

@@ -25,3 +25,30 @@ def test_raises_invalid_if_no_scheme(self):
         self.assertRaises(colander.Invalid,
                           schema.URL().deserialize,
                           url)
+
+
+class ResourceSchemaTest(unittest.TestCase):
+
+    def test_preserves_unknown_fields_when_specified(self):
+        class PreserveSchema(schema.ResourceSchema):
+            class Options:
+                preserve_unknown = True
+
+        schema_instance = PreserveSchema()
+        deserialized = schema_instance.deserialize({'foo': 'bar'})
+        self.assertIn('foo', deserialized)
+        self.assertEquals(deserialized['foo'], 'bar')
+
+    def test_ignore_unknwon_fields_when_specified(self):
+        class PreserveSchema(schema.ResourceSchema):
+            class Options:
+                preserve_unknown = False
+
+        schema_instance = PreserveSchema()
+        deserialized = schema_instance.deserialize({'foo': 'bar'})
+        self.assertNotIn('foo', deserialized)
+
+    def test_ignore_unknwon_fields_by_default(self):
+        schema_instance = schema.ResourceSchema()
+        deserialized = schema_instance.deserialize({'foo': 'bar'})
+        self.assertNotIn('foo', deserialized)