Remove unnecessary checks on update with etag (#63)

* Remove unnecessary checks on update with etag

* Add test of scalar transaction

* Add integration test for scalar transactions

* bump version

Author: andyfangdz

firebase_admin/__init__.py

@@ -23,7 +23,7 @@
 
 # Declaring module version as per https://www.python.org/dev/peps/pep-0396/#specification
 # Update this accordingly for each release.
-__version__ = '2.2.0'
+__version__ = '2.2.1'
 
 _apps = {}
 _apps_lock = threading.RLock()

firebase_admin/db.py

@@ -201,10 +201,6 @@ def update(self, value):
 
     def _update_with_etag(self, value, etag):
         """Sets the data at this location to the specified value, if the etag matches."""
-        if not value or not isinstance(value, dict):
-            raise ValueError('Value argument must be a non-empty dictionary.')
-        if None in value.keys() or None in value.values():
-            raise ValueError('Dictionary must not contain None keys or values.')
         if not isinstance(etag, six.string_types):
             raise ValueError('ETag must be a string.')
 

integration/test_db.py

@@ -178,6 +178,15 @@ def transaction_update(snapshot):
         assert new_value == expected
         assert ref.get() == expected
 
+    def test_transaction_scalar(self, testref):
+        python = testref.parent
+        ref = python.child('users/count')
+        ref.set(42)
+        new_value = ref.transaction(lambda x: x + 1 if x else 1)
+        expected = 43
+        assert new_value == expected
+        assert ref.get() == expected
+
     def test_delete(self, testref):
         python = testref.parent
         ref = python.child('users').push('foo')

tests/test_db.py

@@ -318,6 +318,18 @@ def transaction_update(data):
         assert recorder[1].method == 'PUT'
         assert json.loads(recorder[1].body.decode()) == {'foo1': 'bar1', 'foo2': 'bar2'}
 
+    def test_transaction_scalar(self):
+        ref = db.reference('/test/count')
+        data = 42
+        recorder = self.instrument(ref, json.dumps(data))
+
+        new_value = ref.transaction(lambda x: x + 1 if x else 1)
+        assert new_value == 43
+        assert len(recorder) == 2
+        assert recorder[0].method == 'GET'
+        assert recorder[1].method == 'PUT'
+        assert json.loads(recorder[1].body.decode()) == 43
+
     def test_transaction_error(self):
         ref = db.reference('/test')
         data = {'foo1': 'bar1'}