fix: dynamodb2 conditions

moto/dynamodb2/models.py

@@ -275,9 +275,14 @@ class Table(object):
                         raise ValueError("The conditional request failed")
                 elif key not in current_attr:
                     raise ValueError("The conditional request failed")
-                elif DynamoType(val['Value']).value != current_attr[key].value:
+                elif 'Value' in val and DynamoType(val['Value']).value != current_attr[key].value:
                     raise ValueError("The conditional request failed")
-
+                elif 'ComparisonOperator' in val:
+                    comparison_func = get_comparison_func(val['ComparisonOperator'])
+                    dynamo_types = [DynamoType(ele) for ele in val["AttributeValueList"]]
+                    for t in dynamo_types:
+                        if not comparison_func(current_attr[key].value, t.value):
+                            raise ValueError('The conditional request failed')
         if range_value:
             self.items[hash_value][range_value] = item
         else:

tests/test_dynamodb2/test_dynamodb_table_without_range_key.py

@@ -8,6 +8,7 @@ from freezegun import freeze_time
 from boto.exception import JSONResponseError
 from moto import mock_dynamodb2
 from tests.helpers import requires_boto_gte
+import botocore
 try:
     from boto.dynamodb2.fields import HashKey
     from boto.dynamodb2.table import Table
@@ -469,6 +470,7 @@ def test_update_item_set():
     })
 
 
+
 @mock_dynamodb2
 def test_failed_overwrite():
     table = Table.create('messages', schema=[
@@ -585,6 +587,37 @@ def test_boto3_conditions():
     response['Items'][0].should.equal({"username": "johndoe"})
 
 
+@mock_dynamodb2
+def test_boto3_put_item_conditions_fails():
+    table = _create_user_table()
+    table.put_item(Item={'username': 'johndoe', 'foo': 'bar'})
+    table.put_item.when.called_with(
+        Item={'username': 'johndoe', 'foo': 'baz'},
+        Expected={
+            'foo': {
+                'ComparisonOperator': 'NE',
+                'AttributeValueList': ['bar']
+            }
+        }).should.throw(botocore.client.ClientError)
+
+
+@mock_dynamodb2
+def test_boto3_put_item_conditions_pass():
+    table = _create_user_table()
+    table.put_item(Item={'username': 'johndoe', 'foo': 'bar'})
+    table.put_item(
+        Item={'username': 'johndoe', 'foo': 'baz'},
+        Expected={
+            'foo': {
+                'ComparisonOperator': 'EQ',
+                'AttributeValueList': ['bar']
+            }
+        })
+    returned_item = table.get_item(Key={'username': 'johndoe'})
+    assert dict(returned_item)['Item']['foo'].should.equal("baz")
+
+
+
 @mock_dynamodb2
 def test_scan_pagination():
     table = _create_user_table()