Fix: handle null object correctly (singer-io#38)

karstendick · web-flow · commit addc57b9f4bc · 2017-08-24T15:33:25.000-04:00
* add unit test for null/empty dictionaries

* handle null object correctly

* bump version
diff --git a/setup.py b/setup.py
@@ -4,7 +4,7 @@
 import subprocess
 
 setup(name="singer-python",
-      version='3.1.0',
+      version='3.1.1',
       description="Singer.io utility library",
       author="Stitch",
       classifiers=['Programming Language :: Python :: 3 :: Only'],
diff --git a/singer/transform.py b/singer/transform.py
@@ -124,6 +124,11 @@ def _transform_anyof(self, data, schema, path):
             return False, None
 
     def _transform_object(self, data, schema, path):
+        # only a schema of "null" can match a null value
+        # NB> This will not fail an empty dictionary, i.e. {}
+        if data is None:
+            return False, None
+
         result = {}
         successes = []
         for key, value in data.items():
diff --git a/tests/test_transform.py b/tests/test_transform.py
@@ -214,3 +214,12 @@ def test_unix_seconds_to_datetime(self):
     def test_unix_seconds_to_datetime(self):
         self.assertEqual(unix_milliseconds_to_datetime(0), '1970-01-01T00:00:00.000000Z')
         self.assertEqual(unix_milliseconds_to_datetime(1502722441000), '2017-08-14T14:54:01.000000Z')
+
+    def test_null_object_transform(self):
+        schema =  {"type": "object",
+                   "properties": {"addrs": {"type": ["null", "object"],
+                                            "properties": {"city": {"type": "string"}}}}}
+        none_data = {'addrs': None}
+        self.assertDictEqual(none_data, transform(none_data, schema))
+        empty_data = {'addrs': {}}
+        self.assertDictEqual(empty_data, transform(empty_data, schema))
