feat(dataconnect): Implemented foundational Data Connect client and service architecture

Implemented ConnectorConfig dataclass, DataConnect client instance, _DataConnectService caching layer, and public client() factory function. Fixed mock recursion in test_client_successful using lambda delegation in test_data_connect.py.

Author: mk2023

firebase_admin/dataconnect.py

@@ -1,3 +1,9 @@
+"""Firebase Data Connect module.
+
+This module contains utilities for accessing Firebase Data Connect services associated with
+Firebase apps.
+"""
+
 from dataclasses import dataclass
 from typing import Dict, Optional
 
@@ -7,7 +13,6 @@
 
 _DATA_CONNECT_ATTRIBUTE = '_data_connect_service'
 
-
 @dataclass(frozen=True)
 class ConnectorConfig:
     """A configuration object for DataConnect.
@@ -39,19 +44,15 @@ def __post_init__(self):
 
 class DataConnect:
     """Represents a Firebase Data Connect client instance. 
-       This client provides access to the Firebase Data Connect service for a specific Firebase app and connector configuration.
+       This client provides access to the Firebase Data Connect service 
+       for a specific Firebase app and connector configuration.
     
     Attributes:
         app: The Firebase App instance for this client.
         config: The ConnectorConfig object specifying the service ID, location, and connector name.
     """
     def __init__(self, app: App, config: ConnectorConfig) -> None:
-        """Initializes a DataConnect client instance.
-
-        Args:
-            app: An App instance.
-            config: A ConnectorConfig instance.
-        """
+        """Initializes a DataConnect client instance. """
         self._app: App = app
         self._config = config
 
@@ -81,4 +82,14 @@ def get_client(self, config: ConnectorConfig) -> DataConnect:
 
 
 def client(config: ConnectorConfig, app: Optional[App] = None) -> DataConnect:
-    """Returns a DataConnect client for the specified configuration"""
+    """Returns a DataConnect client for the specified configuration."""
+    if not isinstance(config, ConnectorConfig):
+        raise ValueError("Config must be of type firebase_admin.dataconnect.ConnectorConfig")
+
+    if app is not None and not isinstance(app, App):
+        raise ValueError("App must be of type firebase_admin.App")
+
+    # must check whether app has a _DataConnectService attached to it yet
+    dc_service = _utils.get_app_service(app, _DATA_CONNECT_ATTRIBUTE, _DataConnectService)
+
+    return dc_service.get_client(config)

tests/test_data_connect.py

@@ -13,7 +13,6 @@
     connector="my_connector",
 )
 
-
 class TestConnectorConfig:
   def teardown_method(self, method):
     del method
@@ -90,10 +89,11 @@ def setup_method(self):
     self.config1 = BASE_CONFIG
     self.config2 = dataconnect.ConnectorConfig(service_id='starterproject2', location='us-east4', connector='my_connector2')
 
-  @mock.patch('firebase_admin.dataconnect._DataConnectService.get_client', wraps=dataconnect._DataConnectService.get_client)
+  @mock.patch.object(dataconnect._DataConnectService, 'get_client', autospec=True)
   def test_client_successful(self, mock_get_client):
+    mock_get_client.side_effect = lambda service, config: dataconnect.DataConnect(service._app, config)
     client_instance = dataconnect.client(self.config1, app=self.app)
-    mock_get_client.assert_called_once_with(self.config1)
+    mock_get_client.assert_called_once_with(mock.ANY, self.config1)
     assert isinstance(client_instance, dataconnect.DataConnect)
     assert client_instance.config is self.config1
     assert client_instance.app is self.app