Refine type hints and enhance dynamic dispatch tests for client.GetClassObject, CoGetClassObject and IClassFactory.

comtypes/_post_coinit/misc.py

@@ -142,24 +142,20 @@ def CoCreateInstance(
     return p  # type: ignore
 
 
-if TYPE_CHECKING:
-
-    @overload
-    def CoGetClassObject(
-        clsid: GUID,
-        clsctx: Optional[int] = None,
-        pServerInfo: "Optional[COSERVERINFO]" = None,
-        interface: None = None,
-    ) -> hints.IClassFactory: ...
-    @overload
-    def CoGetClassObject(
-        clsid: GUID,
-        clsctx: Optional[int] = None,
-        pServerInfo: "Optional[COSERVERINFO]" = None,
-        interface: type[_T_IUnknown] = hints.IClassFactory,
-    ) -> _T_IUnknown: ...
-
-
+@overload
+def CoGetClassObject(
+    clsid: GUID,
+    clsctx: Optional[int] = None,
+    pServerInfo: "Optional[COSERVERINFO]" = None,
+    interface: None = None,
+) -> "hints.IClassFactory": ...
+@overload
+def CoGetClassObject(
+    clsid: GUID,
+    clsctx: Optional[int] = None,
+    pServerInfo: "Optional[COSERVERINFO]" = None,
+    interface: type[_T_IUnknown] = IUnknown,
+) -> _T_IUnknown: ...
 def CoGetClassObject(
     clsid: GUID,
     clsctx: Optional[int] = None,

comtypes/client/_create.py

@@ -19,26 +19,26 @@
 #
 # Object creation
 #
-if TYPE_CHECKING:
-
-    @overload
-    def GetClassObject(
-        progid: _UnionT[str, type[CoClass], GUID],
-        clsctx: Optional[int] = None,
-        pServerInfo: Optional[COSERVERINFO] = None,
-        interface: None = None,
-    ) -> hints.IClassFactory: ...
-    @overload
-    def GetClassObject(
-        progid: _UnionT[str, type[CoClass], GUID],
-        clsctx: Optional[int] = None,
-        pServerInfo: Optional[COSERVERINFO] = None,
-        interface: type[_T_IUnknown] = hints.IClassFactory,
-    ) -> _T_IUnknown: ...
-
-
-def GetClassObject(progid, clsctx=None, pServerInfo=None, interface=None):
-    # type: (_UnionT[str, type[CoClass], GUID], Optional[int], Optional[COSERVERINFO], Optional[type[IUnknown]]) -> IUnknown
+@overload
+def GetClassObject(
+    progid: _UnionT[str, type[CoClass], GUID],
+    clsctx: Optional[int] = None,
+    pServerInfo: Optional[COSERVERINFO] = None,
+    interface: None = None,
+) -> "hints.IClassFactory": ...
+@overload
+def GetClassObject(
+    progid: _UnionT[str, type[CoClass], GUID],
+    clsctx: Optional[int] = None,
+    pServerInfo: Optional[COSERVERINFO] = None,
+    interface: type[_T_IUnknown] = IUnknown,
+) -> _T_IUnknown: ...
+def GetClassObject(
+    progid: _UnionT[str, type[CoClass], GUID],
+    clsctx: Optional[int] = None,
+    pServerInfo: Optional[COSERVERINFO] = None,
+    interface: Optional[type[IUnknown]] = None,
+) -> IUnknown:
     """Create and return the class factory for a COM object.
 
     'clsctx' specifies how to create the object, use the CLSCTX_... constants.

comtypes/test/test_classfactory.py

@@ -1,11 +1,13 @@
 import unittest as ut
 
+import comtypes.client
 from comtypes import GUID, CoGetClassObject, IUnknown, shelllink
 from comtypes.server import IClassFactory
 
 CLSID_ShellLink = GUID("{00021401-0000-0000-C000-000000000046}")
 
 REGDB_E_CLASSNOTREG = -2147221164  # 0x80040154
+HKCU = 1  # HKEY_CURRENT_USER
 
 
 class Test_CreateInstance(ut.TestCase):
@@ -27,6 +29,25 @@ def test_returns_iunknown_type_instance(self):
         shlnk.SetDescription("sample")
         self.assertEqual(shlnk.GetDescription(), "sample")
 
+    def test_returns_lazybind_dynamic_dispatch_if_typeinfo_is_available(self):
+        # When `dynamic=True`, objects providing type information will return a
+        # `lazybind.Dispatch` instance.
+        class_factory = comtypes.client.GetClassObject("Scripting.Dictionary")
+        self.assertIsInstance(class_factory, IClassFactory)
+        dic = class_factory.CreateInstance(dynamic=True)
+        self.assertIsInstance(dic, comtypes.client.lazybind.Dispatch)
+        dic.Item["key"] = "value"
+        self.assertEqual(dic.Item["key"], "value")
+
+    def test_returns_fully_dynamic_dispatch_if_typeinfo_is_unavailable(self):
+        # When `dynamic=True`, objects that do NOT provide type information (or
+        # fail to provide it) will return a `dynamic._Dispatch` instance.
+        class_factory = comtypes.client.GetClassObject("WindowsInstaller.Installer")
+        self.assertIsInstance(class_factory, IClassFactory)
+        inst = class_factory.CreateInstance(dynamic=True)
+        self.assertIsInstance(inst, comtypes.client.dynamic._Dispatch)
+        self.assertTrue(inst.RegistryValue(HKCU, r"Control Panel\Desktop"))
+
     def test_raises_valueerror_if_takes_dynamic_true_and_interface_explicitly(self):
         class_factory = CoGetClassObject(CLSID_ShellLink)
         self.assertIsInstance(class_factory, IClassFactory)