adding tests around counter columns

cqlengine/tests/columns/test_counter_column.py

@@ -0,0 +1,64 @@
+from uuid import uuid4
+
+from cqlengine import Model, ValidationError
+from cqlengine import columns
+from cqlengine.management import create_table, delete_table
+from cqlengine.tests.base import BaseCassEngTestCase
+
+
+class TestCounterModel(Model):
+    partition = columns.UUID(primary_key=True, default=uuid4)
+    cluster = columns.UUID(primary_key=True, default=uuid4)
+    counter = columns.Counter()
+
+
+class TestClassConstruction(BaseCassEngTestCase):
+
+    def test_defining_a_non_counter_column_fails(self):
+        """ Tests that defining a non counter column field fails """
+
+    def test_defining_a_primary_key_counter_column_fails(self):
+        """ Tests that defining primary keys on counter columns fails """
+
+
+class TestCounterColumn(BaseCassEngTestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestCounterColumn, cls).setUpClass()
+        delete_table(TestCounterModel)
+        create_table(TestCounterModel)
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestCounterColumn, cls).tearDownClass()
+        delete_table(TestCounterModel)
+
+    def test_updates(self):
+        """ Tests that counter updates work as intended """
+        instance = TestCounterModel.create()
+        instance.counter += 5
+        instance.save()
+
+        actual = TestCounterModel.get(partition=instance.partition)
+        assert actual.counter == 5
+
+    def test_concurrent_updates(self):
+        """ Tests updates from multiple queries reaches the correct value """
+        instance = TestCounterModel.create()
+        new1 = TestCounterModel.get(partition=instance.partition)
+        new2 = TestCounterModel.get(partition=instance.partition)
+
+        new1.counter += 5
+        new1.save()
+        new2.counter += 5
+        new2.save()
+
+        actual = TestCounterModel.get(partition=instance.partition)
+        assert actual.counter == 10
+
+    def test_update_from_none(self):
+        """ Tests that updating from None uses a create statement """
+
+    def test_multiple_inserts(self):
+        """ Tests inserting over existing data works as expected """