unit test for generated IEnum (enthought#468)

comtypes/test/test_enum.py

@@ -0,0 +1,26 @@
+import unittest as ut
+
+import comtypes
+import comtypes.client
+
+
+class Test_Enum(ut.TestCase):
+    def test_enum(self):
+        comtypes.client.GetModule("msvidctl.dll")
+        comtypes.client.GetModule("quartz.dll")
+        from comtypes.gen import MSVidCtlLib as vidlib
+        from comtypes.gen import QuartzTypeLib as quartz
+
+        # FilgraphManager has the same CLSID as FilterGraph
+        filtergraph = comtypes.CoCreateInstance(
+            quartz.FilgraphManager._reg_clsid_,
+            vidlib.IGraphBuilder,
+            comtypes.CLSCTX_INPROC_SERVER,
+        )
+        enum_filters = filtergraph.EnumFilters()
+        # make sure enum_filters is iterable
+        [_ for _ in enum_filters]
+
+
+if __name__ == "__main__":
+    ut.main()