Merge pull request #1376 from dbluhm/fix/injector-typing

feat: add inject_or

aries_cloudagent/admin/request_context.py

@@ -61,8 +61,6 @@ def inject(
         self,
         base_cls: Type[InjectType],
         settings: Mapping[str, object] = None,
-        *,
-        required: bool = True
     ) -> Optional[InjectType]:
         """
         Get the provided instance of a given class identifier.
@@ -75,7 +73,27 @@ def inject(
             An instance of the base class, or None
 
         """
-        return self._context.inject(base_cls, settings, required=required)
+        return self._context.inject(base_cls, settings)
+
+    def inject_or(
+        self,
+        base_cls: Type[InjectType],
+        settings: Mapping[str, object] = None,
+        default: Optional[InjectType] = None,
+    ) -> Optional[InjectType]:
+        """
+        Get the provided instance of a given class identifier or default if not found.
+
+        Args:
+            base_cls: The base class to retrieve an instance of
+            settings: An optional dict providing configuration to the provider
+            default: default return value if no instance is found
+
+        Returns:
+            An instance of the base class, or None
+
+        """
+        return self._context.inject_or(base_cls, settings, default)
 
     def update_settings(self, settings: Mapping[str, object]):
         """Update the current scope with additional settings."""
@@ -96,17 +114,26 @@ def test_context(
     def _test_session(self) -> ProfileSession:
         session = self.profile.session(self._context)
 
-        def _inject(base_cls, required=True):
+        def _inject(base_cls):
             if session._active and base_cls in self.session_inject:
                 ret = self.session_inject[base_cls]
-                if ret is None and required:
+                if ret is None:
                     raise InjectionError(
                         "No instance provided for class: {}".format(base_cls.__name__)
                     )
                 return ret
-            return session._context.injector.inject(base_cls, required=required)
+            return session._context.injector.inject(base_cls)
+
+        def _inject_or(base_cls, default=None):
+            if session._active and base_cls in self.session_inject:
+                ret = self.session_inject[base_cls]
+                if ret is None:
+                    ret = default
+                return ret
+            return session._context.injector.inject_or(base_cls, default)
 
         setattr(session, "inject", _inject)
+        setattr(session, "inject_or", _inject_or)
         return session
 
     def __repr__(self) -> str:

aries_cloudagent/admin/server.py

@@ -251,7 +251,7 @@ def __init__(
         self.webhook_router = webhook_router
         self.websocket_queues = {}
         self.site = None
-        self.multitenant_manager = context.inject(MultitenantManager, required=False)
+        self.multitenant_manager = context.inject_or(MultitenantManager)
 
         self.server_paths = []
 
@@ -293,7 +293,7 @@ async def check_token(request: web.Request, handler):
 
             middlewares.append(check_token)
 
-        collector = self.context.inject(Collector, required=False)
+        collector = self.context.inject_or(Collector)
 
         if self.multitenant_manager:
 
@@ -393,7 +393,7 @@ async def setup_context(request: web.Request, handler):
         self.server_paths = [route.path for route in server_routes]
         app.add_routes(server_routes)
 
-        plugin_registry = self.context.inject(PluginRegistry, required=False)
+        plugin_registry = self.context.inject_or(PluginRegistry)
         if plugin_registry:
             await plugin_registry.register_admin_routes(app)
 
@@ -445,11 +445,11 @@ def sort_dict(raw: dict) -> dict:
         runner = web.AppRunner(self.app)
         await runner.setup()
 
-        plugin_registry = self.context.inject(PluginRegistry, required=False)
+        plugin_registry = self.context.inject_or(PluginRegistry)
         if plugin_registry:
             plugin_registry.post_process_routes(self.app)
 
-        event_bus = self.context.inject(EventBus, required=False)
+        event_bus = self.context.inject_or(EventBus)
         if event_bus:
             event_bus.subscribe(EVENT_PATTERN_WEBHOOK, self._on_webhook_event)
             event_bus.subscribe(EVENT_PATTERN_RECORD, self._on_record_event)
@@ -548,7 +548,7 @@ async def plugins_handler(self, request: web.BaseRequest):
             The module list response
 
         """
-        registry = self.context.inject(PluginRegistry, required=False)
+        registry = self.context.inject_or(PluginRegistry)
         plugins = registry and sorted(registry.plugin_names) or []
         return web.json_response({"result": plugins})
 
@@ -602,7 +602,7 @@ async def status_handler(self, request: web.BaseRequest):
         """
         status = {"version": __version__}
         status["label"] = self.context.settings.get("default_label")
-        collector = self.context.inject(Collector, required=False)
+        collector = self.context.inject_or(Collector)
         if collector:
             status["timing"] = collector.results
         if self.conductor_stats:
@@ -622,7 +622,7 @@ async def status_reset_handler(self, request: web.BaseRequest):
             The web response
 
         """
-        collector = self.context.inject(Collector, required=False)
+        collector = self.context.inject_or(Collector)
         if collector:
             collector.reset()
         return web.json_response({})

aries_cloudagent/admin/tests/test_request_context.py

@@ -22,4 +22,4 @@ async def test_session_inject_x(self):
         test_ctx = test_module.AdminRequestContext.test_context({Collector: None})
         async with test_ctx.session() as test_sesn:
             with self.assertRaises(test_module.InjectionError):
-                test_sesn.inject(Collector, required=True)
+                test_sesn.inject(Collector)

aries_cloudagent/askar/profile.py

@@ -67,7 +67,7 @@ def init_ledger_pool(self):
         if read_only:
             LOGGER.error("Note: setting ledger to read-only mode")
         genesis_transactions = self.settings.get("ledger.genesis_transactions")
-        cache = self.context.injector.inject(BaseCache, required=False)
+        cache = self.context.injector.inject_or(BaseCache)
         self.ledger_pool = IndyVdrLedgerPool(
             pool_name,
             keepalive=keepalive,

aries_cloudagent/config/injection_context.py

@@ -109,8 +109,6 @@ def inject(
         self,
         base_cls: Type[InjectType],
         settings: Mapping[str, object] = None,
-        *,
-        required: bool = True
     ) -> Optional[InjectType]:
         """
         Get the provided instance of a given class identifier.
@@ -123,7 +121,27 @@ def inject(
             An instance of the base class, or None
 
         """
-        return self.injector.inject(base_cls, settings, required=required)
+        return self.injector.inject(base_cls, settings)
+
+    def inject_or(
+        self,
+        base_cls: Type[InjectType],
+        settings: Mapping[str, object] = None,
+        default: Optional[InjectType] = None,
+    ) -> Optional[InjectType]:
+        """
+        Get the provided instance of a given class identifier or default if not found.
+
+        Args:
+            base_cls: The base class to retrieve an instance of
+            settings: An optional dict providing configuration to the provider
+            default: default return value if no instance is found
+
+        Returns:
+            An instance of the base class, or None
+
+        """
+        return self.injector.inject_or(base_cls, settings, default)
 
     def copy(self) -> "InjectionContext":
         """Produce a copy of the injector instance."""

aries_cloudagent/config/injector.py

@@ -51,19 +51,19 @@ def get_provider(self, base_cls: Type[InjectType]):
         """Find the provider associated with a class binding."""
         return self._providers.get(base_cls)
 
-    def inject(
+    def inject_or(
         self,
         base_cls: Type[InjectType],
         settings: Mapping[str, object] = None,
-        *,
-        required: bool = True,
+        default: Optional[InjectType] = None,
     ) -> Optional[InjectType]:
         """
-        Get the provided instance of a given class identifier.
+        Get the provided instance of a given class identifier or default if not found.
 
         Args:
-            cls: The base class to retrieve an instance of
-            params: An optional dict providing configuration to the provider
+            base_cls: The base class to retrieve an instance of
+            settings: An optional dict providing configuration to the provider
+            default: default return value if no instance is found
 
         Returns:
             An instance of the base class, or None
@@ -80,17 +80,37 @@ def inject(
             result = provider.provide(ext_settings, self)
         else:
             result = None
-        if result is None:
-            if required:
-                raise InjectionError(
-                    "No instance provided for class: {}".format(base_cls.__name__)
-                )
-        elif not isinstance(result, base_cls) and self.enforce_typing:
+
+        if result and not isinstance(result, base_cls) and self.enforce_typing:
             raise InjectionError(
                 "Provided instance does not implement the base class: {}".format(
                     base_cls.__name__
                 )
             )
+
+        return result if result is not None else default
+
+    def inject(
+        self,
+        base_cls: Type[InjectType],
+        settings: Mapping[str, object] = None,
+    ) -> InjectType:
+        """
+        Get the provided instance of a given class identifier.
+
+        Args:
+            cls: The base class to retrieve an instance of
+            params: An optional dict providing configuration to the provider
+
+        Returns:
+            An instance of the base class, or None
+
+        """
+        result = self.inject_or(base_cls, settings)
+        if result is None:
+            raise InjectionError(
+                "No instance provided for class: {}".format(base_cls.__name__)
+            )
         return result
 
     def copy(self) -> BaseInjector:

aries_cloudagent/config/ledger.py

@@ -63,7 +63,7 @@ async def ledger_config(
 
     session = await profile.session()
 
-    ledger = session.inject(BaseLedger, required=False)
+    ledger = session.inject_or(BaseLedger)
     if not ledger:
         LOGGER.info("Ledger instance not provided")
         return False

aries_cloudagent/config/provider.py

@@ -129,7 +129,7 @@ def provide(self, config: BaseSettings, injector: BaseInjector):
         """Provide the object instance given a config and injector."""
         instance = self._provider.provide(config, injector)
         if self._methods:
-            collector: Collector = injector.inject(Collector, required=False)
+            collector: Collector = injector.inject_or(Collector)
             if collector:
                 collector.wrap(
                     instance, self._methods, ignore_missing=self._ignore_missing

aries_cloudagent/config/tests/test_injection_context.py

@@ -53,7 +53,7 @@ def test_settings_scope(self):
 
     async def test_inject_simple(self):
         """Test a basic injection."""
-        assert self.test_instance.inject(str, required=False) is None
+        assert self.test_instance.inject_or(str) is None
         with self.assertRaises(InjectionError):
             self.test_instance.inject(str)
         self.test_instance.injector.bind_instance(str, self.test_value)
@@ -65,10 +65,10 @@ async def test_inject_simple(self):
     async def test_inject_scope(self):
         """Test a scoped injection."""
         context = self.test_instance.start_scope(self.test_scope)
-        assert context.inject(str, required=False) is None
+        assert context.inject_or(str) is None
         context.injector.bind_instance(str, self.test_value)
         assert context.inject(str) is self.test_value
-        assert self.test_instance.inject(str, required=False) is None
+        assert self.test_instance.inject_or(str) is None
         root = context.injector_for_scope(context.ROOT_SCOPE)
-        assert root.inject(str, required=False) is None
-        assert self.test_instance.inject(str, required=False) is None
+        assert root.inject_or(str) is None
+        assert self.test_instance.inject_or(str) is None

aries_cloudagent/config/tests/test_injector.py

@@ -43,7 +43,7 @@ def test_settings_init(self):
 
     def test_inject_simple(self):
         """Test a basic injection."""
-        assert self.test_instance.inject(str, required=False) is None
+        assert self.test_instance.inject_or(str) is None
         with self.assertRaises(InjectionError):
             self.test_instance.inject(str)
         with self.assertRaises(ValueError):
@@ -75,7 +75,7 @@ def test_bad_provider(self):
         self.test_instance.bind_provider(str, MockProvider(None))
         with self.assertRaises(InjectionError):
             self.test_instance.inject(str)
-        self.test_instance.inject(str, required=False)
+        self.test_instance.inject_or(str)
         self.test_instance.bind_provider(str, MockProvider(1))
         self.test_instance.clear_binding(str)
         assert self.test_instance.get_provider(str) is None
@@ -139,3 +139,9 @@ def test_inject_cached(self):
         i1 = self.test_instance.inject(MockInstance)
         i2 = self.test_instance.inject(MockInstance)
         assert i1 is i2
+
+    def test_falsey_still_returns(self):
+        """Test the injector still returns falsey values."""
+        self.test_instance.bind_instance(dict, dict())
+        assert self.test_instance.inject_or(dict) is not None
+        assert self.test_instance.inject(dict) is not None

aries_cloudagent/config/tests/test_wallet.py

@@ -37,8 +37,8 @@ async def setUp(self):
             transaction=async_mock.CoroutineMock(return_value=self.session),
         )
 
-        def _inject(cls, required=True):
-            return self.injector.inject(cls, required=required)
+        def _inject(cls):
+            return self.injector.inject(cls)
 
         self.session.inject = _inject
         self.context = InjectionContext()

aries_cloudagent/core/conductor.py

@@ -121,7 +121,7 @@ async def setup(self):
         self.dispatcher = Dispatcher(self.root_profile)
         await self.dispatcher.setup()
 
-        wire_format = context.inject(BaseWireFormat, required=False)
+        wire_format = context.inject_or(BaseWireFormat)
         if wire_format and hasattr(wire_format, "task_queue"):
             wire_format.task_queue = self.dispatcher.task_queue
 
@@ -159,7 +159,7 @@ async def setup(self):
                 raise
 
         # Fetch stats collector, if any
-        collector = context.inject(Collector, required=False)
+        collector = context.inject_or(Collector)
         if collector:
             # add stats to our own methods
             collector.wrap(
@@ -358,7 +358,7 @@ async def stop(self, timeout=1.0):
             shutdown.run(self.outbound_transport_manager.stop())
 
         # close multitenant profiles
-        multitenant_mgr = self.context.inject(MultitenantManager, required=False)
+        multitenant_mgr = self.context.inject_or(MultitenantManager)
         if multitenant_mgr:
             for profile in multitenant_mgr._instances.values():
                 shutdown.run(profile.close())

aries_cloudagent/core/dispatcher.py

@@ -57,7 +57,7 @@ def __init__(self, profile: Profile):
 
     async def setup(self):
         """Perform async instance setup."""
-        self.collector = self.profile.inject(Collector, required=False)
+        self.collector = self.profile.inject_or(Collector)
         max_active = int(os.getenv("DISPATCHER_MAX_ACTIVE", 50))
         self.task_queue = TaskQueue(
             max_active=max_active, timed=bool(self.collector), trace_fn=self.log_task