Fix update item without get first resetting version to 1 (#1247)

tests/integration/model_integration_test.py

@@ -142,3 +142,61 @@ class Meta:
 
             version_invalid = VersionAttribute()
     assert str(e.value) == 'The model has more than one Version attribute: version, version_invalid'
+
+
+@pytest.mark.ddblocal
+def test_update_model_with_version_attribute_without_get(ddb_url):
+    class TestModel(Model):
+        """
+        A model for testing
+        """
+        class Meta:
+            region = 'us-east-1'
+            table_name = 'pynamodb-ci'
+            host = ddb_url
+        forum = UnicodeAttribute(hash_key=True)
+        score = NumberAttribute(null=True)
+        version = VersionAttribute()
+
+    if TestModel.exists():
+        TestModel.delete_table()
+    TestModel.create_table(read_capacity_units=1, write_capacity_units=1, wait=True)
+
+    obj = TestModel('1')
+    obj.save()
+    assert TestModel.get('1').version == 1
+    obj.score = 1 
+    obj.save()
+    assert TestModel.get('1').version == 2
+
+    obj_by_key = TestModel('1')  # try to update item without getting it first
+    obj_by_key.update(
+        actions=[
+            TestModel.score.set(2),  # no version increment
+        ],
+        add_version_condition=False
+    )
+    updated_obj = TestModel.get('1')
+    assert updated_obj.score == 2
+    assert updated_obj.version == 2
+
+    obj_2 = TestModel('2')
+    obj_2.save()
+    assert TestModel.get('2').version == 1
+    obj_2.score = 1 
+    obj_2.save()
+    assert TestModel.get('2').version == 2
+
+    obj_2_by_key = TestModel('2')  # try to update item without getting it first
+    obj_2_by_key.update(
+        actions=[
+            TestModel.score.set(2),
+            TestModel.version.set(TestModel.version + 1)  # increment version manually
+        ],
+        add_version_condition=False
+    )
+    updated_obj_2 = TestModel.get('2')
+    assert updated_obj_2.score == 2
+    assert updated_obj_2.version == 3
+
+    TestModel.delete_table()

tests/integration/test_transaction_integration.py

@@ -428,3 +428,51 @@ def test_transaction_write_with_version_attribute_condition_failure(connection):
     assert len(exc_info.value.cancellation_reasons) == 1
     assert exc_info.value.cancellation_reasons[0].code == 'ConditionalCheckFailed'
     assert Foo.Meta.table_name in exc_info.value.cause.MSG_TEMPLATE
+
+
+@pytest.mark.ddblocal
+def test_transaction_write_without_version_attribute_condition(connection):
+    foo = Foo(22)
+    foo.save()
+    assert Foo.get(22).version == 1
+    foo.star = 'initial_update'
+    foo.save()
+    assert Foo.get(22).version == 2
+
+    foo2 = Foo(22)  # try to update a field without getting the item first
+
+    with TransactWrite(connection=connection) as transaction:
+        transaction.update(
+            foo2,
+            actions=[
+                Foo.star.set('birdistheword'),
+            ],
+            add_version_condition=False,
+        )
+
+    foo_updated =  Foo.get(22)
+    assert foo_updated.version == 2  # should not modify the version
+    assert foo_updated.star == 'birdistheword'
+
+
+@pytest.mark.ddblocal
+def test_transaction_write_increment_version_without_version_attribute_condition(connection):
+    foo = Foo(23)
+    foo.save()
+    assert Foo.get(23).version == 1
+
+    foo2 = Foo(23)
+
+    with TransactWrite(connection=connection) as transaction:
+        transaction.update(
+            foo2,
+            actions=[
+                Foo.star.set('birdistheword'),
+                Foo.version.set(Foo.version + 1),
+            ],
+            add_version_condition=False,
+        )
+
+    foo_updated =  Foo.get(23)
+    assert foo_updated.star == 'birdistheword'
+    assert foo_updated.version == 3