new_contents: # Copyright 2019 ScyllaDB
  #
  # This file is part of Scylla.
  #
  # Scylla is free software: you can redistribute it and/or modify
  # it under the terms of the GNU Affero General Public License as published by
  # the Free Software Foundation, either version 3 of the License, or
  # (at your option) any later version.
  #
  # Scylla is distributed in the hope that it will be useful,
  # but WITHOUT ANY WARRANTY; without even the implied warranty of
  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  # GNU General Public License for more details.
  #
  # You should have received a copy of the GNU Affero General Public License
  # along with Scylla.  If not, see <http://www.gnu.org/licenses/>.
  
  # Tests for the ConditionExpression parameter
  
  import pytest
  from botocore.exceptions import ClientError
  from util import random_string
  
  # Test that ConditionExpression works as expected
  @pytest.mark.xfail(reason="ConditionExpression not yet implemented")
  def test_update_condition_expression(test_table_s):
      p = random_string()
      test_table_s.update_item(Key={'p': p},
          UpdateExpression='SET b = :val1',
          ExpressionAttributeValues={':val1': 4})
      test_table_s.update_item(Key={'p': p},
          UpdateExpression='SET b = :val1',
          ConditionExpression='b = :oldval',
          ExpressionAttributeValues={':val1': 6, ':oldval': 4})
      with pytest.raises(ClientError, match='ConditionalCheckFailedException.*'):
          test_table_s.update_item(Key={'p': p},
              UpdateExpression='SET b = :val1',
              ConditionExpression='b = :oldval',
              ExpressionAttributeValues={':val1': 8, ':oldval': 4})
      assert test_table_s.get_item(Key={'p': p}, ConsistentRead=True)['Item'] == {'p': p, 'b': 6}
  
subject: add initial test_condition_expression file