TDL-13692: Missing parent objects from projection expression causes k…

…ey error and TDL-16140: Fix key error and index error while applying projection expression (#35)

* added code change for handling key error and index error

* resolve pylint error

* updated the unittests

* updated config.yml to run unittest to run on CCi

* added unittests

* updated the code to handle child dict data

* added comments with example for projection

* updated config.yml file and resolved PR review comments

* resolve slack failure error in config file

* updated version 2 to 2.1

* remoed SCENARIO from the test cases

* resolved comments

* reverted changes

* added tap-tester-venv, tap_tester_sandbox and check for verifying that we replicated records

Co-authored-by: namrata270998 <namrata.brahmbhatt@crestdatasys.com>

tap_dynamodb/deserialize.py

@@ -63,23 +63,31 @@ def _apply_projection(self, record, breadcrumb, output):
                 breadcrumb_key = breadcrumb[0].split('[')[0]
                 index = int(breadcrumb[0].split('[')[1].split(']')[0])
                 if output.get(breadcrumb_key):
-                    output[breadcrumb_key].append(record[breadcrumb_key][index])
+                    # only prepare output if the list field contains data at that index position in record
+                    if len(record.get(breadcrumb_key)) > index:
+                        output[breadcrumb_key].append(record[breadcrumb_key][index])
                 else:
-                    output[breadcrumb_key] = [record[breadcrumb_key][index]]
-
+                    output[breadcrumb_key] = []
+                    # only prepare output if the list field contains data at that index position in record
+                    if record.get(breadcrumb_key) and len(record.get(breadcrumb_key)) > index:
+                        output[breadcrumb_key].append(record[breadcrumb_key][index])
             else:
                 output[breadcrumb[0]] = record.get(breadcrumb[0])
         else:
             if '[' in breadcrumb[0]:
                 breadcrumb_key = breadcrumb[0].split('[')[0]
                 index = int(breadcrumb[0].split('[')[1].split(']')[0])
-                if output.get(breadcrumb_key) is None:
+                if not output.get(breadcrumb_key):
                     output[breadcrumb_key] = [{}]
-                self._apply_projection(record[breadcrumb_key][index], breadcrumb[1:], output[breadcrumb_key][0])
+                # only prepare output if the list field contains data at that index position in record
+                if record.get(breadcrumb_key) and len(record.get(breadcrumb_key)) > index:
+                    self._apply_projection(record[breadcrumb_key][index], breadcrumb[1:], output[breadcrumb_key][0])
             else:
                 if output.get(breadcrumb[0]) is None:
                     output[breadcrumb[0]] = {}
-                self._apply_projection(record[breadcrumb[0]], breadcrumb[1:], output[breadcrumb[0]])
+                # keep empty dict if the data is not found in the record
+                if record.get(breadcrumb[0]):
+                    self._apply_projection(record.get(breadcrumb[0], {}), breadcrumb[1:], output[breadcrumb[0]])
 
     def apply_projection(self, record, projections):
         output = {}

tests/test_dynamodb_log_based_parent_child_data.py

@@ -0,0 +1,104 @@
+from boto3.dynamodb.types import TypeSerializer
+
+from tap_tester import connections
+from tap_tester import menagerie
+from tap_tester import runner
+
+from base import TestDynamoDBBase
+
+class DynamoDBLogBasedParentChildData(TestDynamoDBBase):
+    """
+        Test case for verifying:
+        - The tap does not break when the parent data is not found and the user is requesting for child data
+        - The tap does not break when the data a specific position is not found in the record
+    """
+
+    # expected table configs
+    def expected_table_config(self):
+        return [
+            {
+                'TableName': 'simple_table_1',
+                'HashKey': 'int_id',
+                'HashType': 'N',
+                'generator': self.generate_items,
+                'num_rows': 10,
+                'ProjectionExpression': 'int_id, map_field.map_entry_1, test_list_1[0], test_list_2[0], test_list_2[1], test_list_3[0].test_field',
+                'top_level_keys': {'int_id', 'map_field'},
+                'nested_map_keys': {'map_field': {'map_entry_1'}},
+            }
+        ]
+
+    # send desired data for testing
+    def generate_items(self, num_items, start_key=0):
+        serializer = TypeSerializer()
+        for i in range(start_key, start_key + num_items):
+            record = {
+                'int_id': i,
+                'string_field': self.random_string_generator(),
+                'test_list_2': ['list_2_data']
+            }
+            yield serializer.serialize(record)
+
+    @staticmethod
+    def name():
+        return "tap_tester_dynamodb_parent_child_data"
+
+    def test_run(self):
+        (table_configs, conn_id, expected_streams) = self.pre_sync_test()
+
+        # Select 'simple_table_1' stream and add replication method and projection
+        found_catalogs = menagerie.get_catalogs(conn_id)
+        for stream_catalog in found_catalogs:
+            annotated_schema = menagerie.get_annotated_schema(conn_id, stream_catalog['stream_id'])
+            additional_md = [
+                {
+                    "breadcrumb": [],
+                    "metadata": {
+                        'replication-method': 'LOG_BASED',
+                        'tap-mongodb.projection': table_configs[0]['ProjectionExpression']
+                    }
+                }
+            ]
+            connections.select_catalog_and_fields_via_metadata(conn_id,
+                                                               stream_catalog,
+                                                               annotated_schema,
+                                                               additional_md)
+
+        # diable stream to force shard to close
+        self.disableStreams(expected_streams)
+        # run sync mode 1st time as for the 1st time it sync in FULL_TABLE mode
+        sync_job_name = runner.run_sync_mode(self, conn_id)
+
+        exit_status = menagerie.get_exit_status(conn_id, sync_job_name)
+        menagerie.verify_sync_exit_status(self, exit_status, sync_job_name)
+
+        # collect state file
+        state = menagerie.get_state(conn_id)
+        state_version = menagerie.get_state_version(conn_id)
+
+        # delete 'finished_shards' for every streams from the state file as we want to run 2nd sync
+        for config in table_configs:
+            table_name = config['TableName']
+            del state['bookmarks'][table_name]['finished_shards']
+        menagerie.set_state(conn_id, state, version=state_version)
+
+        # run the sync mode 2nd time, noow it will run in LOG_BASED mode
+        sync_job_name = runner.run_sync_mode(self, conn_id)
+
+        # get data
+        messages_by_stream = runner.get_records_from_target_output()
+
+        for stream in expected_streams:
+            messages = messages_by_stream.get(stream).get('messages')
+            records = [message.get('data') for message in messages if message.get('action') == 'upsert']
+            # verify that we replicated records
+            self.assertTrue(len(records) > 0)
+            for record in records:
+
+                # verify that we get 'None' for child data when parent data is not found
+                self.assertIsNone(record.get('map_field').get('map_entry_1'))
+                # verify that we only get the available data if the data at a particular index is not found
+                self.assertEquals(record.get('test_list_1'), [])
+                self.assertEquals(record.get('test_list_2'), ['list_2_data'])
+                # verify that we got empty map if the parent data at a particular index is not found for child data
+                self.assertEquals(record.get('test_list_3'), [{}])

tests/unittests/test_deserializer.py

@@ -0,0 +1,130 @@
+import unittest
+from tap_dynamodb import deserialize
+
+class TestDeserializer(unittest.TestCase):
+
+    def test_projection_expression_all_list_data_not_found(self):
+        '''
+            Verify that we get empty list if the data is not found in the record
+            Example Projection: Artist, metadata[0]
+            Stream Record: {'Artist': 'No One You Know'}
+        '''
+        mock_record = {'Artist': 'No One You Know5'}
+        mock_projections =  [['Artist'], ['metadata[0]']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # verify that we get empty list if the data is not found in the record
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': []})
+
+    def test_projection_expression_all_list_data_not_found_positive(self):
+        '''
+            Verify that we get empty list if the data is not found in the record
+            Example Projection: Artist, metadata[0]
+            Stream Record: {'Artist': 'No One You Know5', 'metadata': ['test']}
+        '''
+        mock_record = {'Artist': 'No One You Know5', 'metadata': ['test']}
+        mock_projections =  [['Artist'], ['metadata[0]']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # verify that we get empty list if the data is not found in the record
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': ['test']})
+
+    def test_projection_expression_some_list_data_not_found(self):
+        '''
+            Verify that we only get the available data in the list when user expect the data that is not available
+            Example Projection: Artist, metadata[0], metadata[1]
+            Stream Record: {'Artist': 'No One You Know','metadata': ['test1']}
+        '''
+        mock_record = {'Artist': 'No One You Know5','metadata': ['test1']}
+        mock_projections =  [['Artist'], ['metadata[0]'], ['metadata[1]']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # verify that we only get the available data in the list when user expect the data that is not available
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': ['test1']})
+
+    def test_projection_expression_some_list_data_not_found_positive(self):
+        '''
+            Verify that we only get the available data in the list when user expect the data that is not available
+            Example Projection: Artist, metadata[0], metadata[1]
+            Stream Record: {'Artist': 'No One You Know','metadata': ['test1', 'test2']}
+        '''
+        mock_record = {'Artist': 'No One You Know5','metadata': ['test1', 'test2']}
+        mock_projections =  [['Artist'], ['metadata[0]'], ['metadata[1]']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # verify that we only get the available data in the list when user expect the data that is not available
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': ['test1', 'test2']})
+
+    def test_projection_expression_parent_child_data_list(self):
+        '''
+            Verify that we get empty dict when the element in the list is parent element and it is not found
+            Example Projection: Artist, metadata[0].Age
+            Stream Record: {'Artist': 'No One You Know'}
+        '''
+        mock_record = {'Artist': 'No One You Know5'}
+        mock_projections =  [['Artist'], ['metadata[0]', 'Age']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # verify that we get empty dict when the element in the list is parent element and it is not found
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': [{}]})
+
+    def test_projection_expression_parent_child_data_list_positive(self):
+        '''
+            Verify that we get empty dict when the element in the list is parent element and it is not found
+            Example Projection: Artist, metadata[0].Age
+            Stream Record: {'Artist': 'No One You Know5', 'metadata': [{'Age': 'Test'}]}
+        '''
+        mock_record = {'Artist': 'No One You Know5', 'metadata': [{'Age': 'Test'}]}
+        mock_projections =  [['Artist'], ['metadata[0]', 'Age']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # verify that we get empty dict when the element in the list is parent element and it is not found
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': [{'Age': 'Test'}]})
+
+    def test_projection_expression_parent_child_data_dictionary(self):
+        '''
+            Veriy that we get None when the parent data is not found and we are requesting for child data
+            Example Projection: Artist, metadata.inner_metadata
+            Stream Record: {'Artist': 'No One You Know'}
+        '''
+        mock_record = {'Artist': 'No One You Know5'}
+        mock_projections =  [['Artist'], ['metadata', 'inner_metadata']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # veriy that we get None when the parent data is not found
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': {}})
+
+    def test_projection_expression_parent_child_data_dictionary_positive(self):
+        '''
+            Veriy that we get None when the parent data is not found and we are requesting for child data
+            Example Projection: Artist, metadata.inner_metadata
+            Stream Record: {'Artist': 'No One You Know5', 'metadata': {'inner_metadata': 'Test'}}
+        '''
+        mock_record = {'Artist': 'No One You Know5', 'metadata': {'inner_metadata': 'Test'}}
+        mock_projections =  [['Artist'], ['metadata', 'inner_metadata']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # veriy that we get None when the parent data is not found
+        self.assertEquals(output, {'Artist': 'No One You Know5', 'metadata': {'inner_metadata': 'Test'}})
+
+    def test_projection_expression_parent_child_data_list_different_order(self):
+        '''
+            Veriy that we get no error when add list projection in decreasing order and it is not found
+            Example Projection: metadata[1], metadata[0].inner_metadata
+            Stream Record: {'metadata': [{'inner_metadata': 'Test'}]}
+        '''
+        mock_record = {'metadata': [{'inner_metadata': 'Test'}]}
+        mock_projections =  [['metadata[1]'], ['metadata[0]', 'inner_metadata']]
+
+        deserializer = deserialize.Deserializer()
+        output = deserializer.apply_projection(mock_record, mock_projections)
+        # veriy that we get no error when add list projection in decreasing order and it is not found
+        self.assertEquals(output, {'metadata': [{'inner_metadata': 'Test'}]})