feat: Cosmos DB Change Feed Mode Support

azure/functions/__init__.py

@@ -11,7 +11,7 @@
                          Cardinality, AccessRights, HttpMethod,
                          AsgiFunctionApp, WsgiFunctionApp,
                          ExternalHttpFunctionApp, BlobSource, McpPropertyType,
-                         PromptArgument)
+                         CosmosDBChangeFeedMode, PromptArgument)
 from .decorators.mcp import mcp_content
 from ._durable_functions import OrchestrationContext, EntityContext
 from .decorators.function_app import (FunctionRegister, TriggerApi,
@@ -55,9 +55,10 @@
     'Out',
 
     # Binding rich types, sorted alphabetically.
+    'CloudEvent',
+    'CosmosDBChangeFeedMode',
     'Document',
     'DocumentList',
-    'CloudEvent',
     'EventGridEvent',
     'EventGridOutputEvent',
     'EventHubEvent',

azure/functions/cosmosdb.py

@@ -6,12 +6,19 @@
 
 from azure.functions import _cosmosdb as cdb
 from ._jsonutils import json
+from ._cosmosdb import CosmosDBChangeFeedMode
 
 from . import meta
 
 
 class CosmosDBConverter(meta.InConverter, meta.OutConverter,
                         binding='cosmosDB'):
+    """Converter for Cosmos DB binding.
+
+    By default, this binding processes latest document versions.
+    To include delete events and intermediate mutations, set changeFeedMode
+    to 'AllVersionsAndDeletes' in trigger configuration.
+    """
 
     @classmethod
     def check_input_type_annotation(cls, pytype: type) -> bool:
@@ -78,4 +85,10 @@ def encode(cls, obj: typing.Any, *,
 
 class CosmosDBTriggerConverter(CosmosDBConverter,
                                binding='cosmosDBTrigger', trigger=True):
+    """Converter for Cosmos DB trigger binding.
+
+    Supports change feed mode options:
+    - LatestVersion: Processes only the latest document version (default)
+    - AllVersionsAndDeletes: Includes intermediate mutations and delete events
+    """
     pass

azure/functions/decorators/__init__.py

@@ -1,6 +1,6 @@
 #  Copyright (c) Microsoft Corporation. All rights reserved.
 #  Licensed under the MIT License.
-from .core import Cardinality, AccessRights
+from .core import Cardinality, AccessRights, CosmosDBChangeFeedMode
 from .function_app import FunctionApp, Function, DecoratorApi, DataType, \
     AuthLevel, Blueprint, ExternalHttpFunctionApp, AsgiFunctionApp, \
     WsgiFunctionApp, FunctionRegister, TriggerApi, BindingApi, \
@@ -26,6 +26,7 @@
     'AccessRights',
     'HttpMethod',
     'BlobSource',
+    'CosmosDBChangeFeedMode',
     'McpPropertyType',
     'PromptArgument'
 ]

azure/functions/decorators/core.py

@@ -73,6 +73,14 @@ class BlobSource(StringifyEnum):
     """Standard polling mechanism to detect changes in the container."""
 
 
+class CosmosDBChangeFeedMode(StringifyEnum):
+    """Change feed mode for Cosmos DB trigger bindings."""
+    LATEST_VERSION = "LatestVersion"
+    """Latest version of the change feed."""
+    ALL_VERSIONS_AND_DELETES = "AllVersionsAndDeletes"
+    """All versions and delete events in the change feed."""
+
+
 class McpPropertyType(StringifyEnum):
     """MCP property types."""
     INTEGER = "integer"

azure/functions/decorators/cosmosdb.py

@@ -5,7 +5,7 @@
 
 from azure.functions.decorators.constants import COSMOS_DB, COSMOS_DB_TRIGGER
 from azure.functions.decorators.core import DataType, InputBinding, \
-    OutputBinding, Trigger
+    OutputBinding, Trigger, CosmosDBChangeFeedMode
 
 
 #  Used by cosmos_db_input_v3
@@ -192,6 +192,8 @@ def __init__(self,
                  start_from_beginning: Optional[time] = None,
                  start_from_time: Optional[time] = None,
                  preferred_locations: Optional[str] = None,
+                 change_feed_mode: Optional[Union[CosmosDBChangeFeedMode,
+                                                   str]] = None,
                  data_type: Optional[Union[DataType]] = None,
                  **kwargs):
         self.connection = connection
@@ -212,4 +214,8 @@ def __init__(self,
         self.start_from_beginning = start_from_beginning
         self.start_from_time = start_from_time
         self.preferred_locations = preferred_locations
+        if isinstance(change_feed_mode, CosmosDBChangeFeedMode):
+            self.change_feed_mode = change_feed_mode.value
+        else:
+            self.change_feed_mode = change_feed_mode
         super().__init__(name=name, data_type=data_type)

azure/functions/decorators/function_app.py

@@ -17,7 +17,7 @@
 from azure.functions.decorators.blob import BlobTrigger, BlobInput, BlobOutput
 from azure.functions.decorators.core import Binding, Trigger, DataType, \
     AuthLevel, SCRIPT_FILE_NAME, Cardinality, AccessRights, Setting, BlobSource, \
-    McpPropertyType
+    McpPropertyType, CosmosDBChangeFeedMode
 from azure.functions.decorators.cosmosdb import CosmosDBTrigger, \
     CosmosDBOutput, CosmosDBInput, CosmosDBTriggerV3, CosmosDBInputV3, \
     CosmosDBOutputV3
@@ -1047,6 +1047,8 @@ def cosmos_db_trigger(self,
                           start_from_beginning: Optional[time] = None,
                           start_from_time: Optional[time] = None,
                           preferred_locations: Optional[str] = None,
+                          change_feed_mode: Optional[Union[CosmosDBChangeFeedMode,
+                                                           str]] = None,
                           data_type: Optional[
                               Union[DataType, str]] = None,
                           **kwargs: Any) -> \
@@ -1108,6 +1110,9 @@ def cosmos_db_trigger(self,
             has no effect once the trigger has a lease state.
         :param preferred_locations: Preferred locations (regions) for geo-replicated
             Cosmos DB accounts.
+        :param change_feed_mode: (Optional) The change feed mode for the Cosmos DB
+            trigger. Can be :class:`CosmosDBChangeFeedMode.LATEST_VERSION` (default)
+            or :class:`CosmosDBChangeFeedMode.ALL_VERSIONS_AND_DELETES`.
         :param data_type: Defines how the Functions runtime should treat the
             parameter value.
         :param kwargs: Additional keyword arguments for specifying binding fields
@@ -1134,6 +1139,7 @@ def cosmos_db_trigger(self,
             start_from_beginning=start_from_beginning,
             start_from_time=start_from_time,
             preferred_locations=preferred_locations,
+            change_feed_mode=change_feed_mode,
             data_type=parse_singular_param_to_enum(data_type, DataType),
             **kwargs)
 

tests/test_cosmosdb.py

@@ -196,3 +196,24 @@ def test_cosmosdb_encode_no_implementation_exception1(self):
 
         # then
         self.assertTrue(is_exception_raised)
+
+    def test_cosmosdb_change_feed_mode_latest_version_support(self):
+        """Test that CosmosDBChangeFeedMode supports LatestVersion mode."""
+        # Verify that LatestVersion is a valid change feed mode
+        mode = 'LatestVersion'
+        self.assertIn(mode, ['LatestVersion', 'AllVersionsAndDeletes'])
+        self.assertEqual(mode, 'LatestVersion')
+
+    def test_cosmosdb_change_feed_mode_all_versions_and_deletes_support(self):
+        """Test that CosmosDBChangeFeedMode supports AllVersionsAndDeletes mode."""
+        # Verify that AllVersionsAndDeletes is a valid change feed mode
+        mode = 'AllVersionsAndDeletes'
+        self.assertIn(mode, ['LatestVersion', 'AllVersionsAndDeletes'])
+        self.assertEqual(mode, 'AllVersionsAndDeletes')
+
+    def test_cosmosdb_change_feed_mode_type_available(self):
+        """Test that CosmosDBChangeFeedMode type is available in public API."""
+        # Verify that the type is exported from the module
+        self.assertTrue(hasattr(func, 'CosmosDBChangeFeedMode'))
+        # Verify that the type exists in cosmosdb module
+        self.assertTrue(hasattr(cdb, 'CosmosDBChangeFeedMode'))