[test\test_basic.py] Use OleDLL instead of windll

[moi15moi]

See #735

IUnknown to ICreateTypeLib2 because CreateTypeLib2 doesn't take IUnknown as a parameter.

[junkmd]

Here’s my perspective on this test:

Given the objectives of test_refcounts and test_qi, any test double that serves as a pointer to IUnknown should suffice. However, I think it's better to avoid approaches that rely on specific custom interface definitions.
Since test_identity calls CreateTypeLib (that indirectly calls _CreateTypeLib2), I don’t see much value in testing _CreateTypeLib2 bound to ICreateTypeLib2 specifically in this context.

comtypes/comtypes/test/test_basic.py

Lines 101 to 115 in a9f0558

	def test_identity(self):
	# COM indentity rules
	# these should be identical
	a = POINTER(IUnknown)()
	b = POINTER(IUnknown)()
	self.assertEqual(a, b)
	self.assertEqual(hash(a), hash(b))
	from comtypes.typeinfo import CreateTypeLib
	# we do not save the lib, so no file will be created.
	# these should NOT be identical
	a = CreateTypeLib("blahblah")
	b = CreateTypeLib("spam")

It might be worth considering defining a single-responsibility function to create this test double, duplicating _CreateTypeLib2 from typeinfo.py and make the “_CreateTypeLib2 that accepts POINTER(IUnknown)”.

What are your thoughts on this?

[moi15moi]

I prefer to adhere strictly to the actual parameters of CreateTypeLib2 to maintain accuracy and consistency.

Since IUnknown behaves like an abstract class, there is no direct way to test refcounts and QueryInterface and I think it's totally normal. However, I believe it would be beneficial to include a comment indicating that the purpose is to test the behavior of IUnknown even if we use ICreateTypeLib2.

What do you think?

[junkmd]

However, I believe it would be beneficial to include a comment indicating that the purpose is to test the behavior of IUnknown even if we use ICreateTypeLib2.

Indeed, comments can be a powerful tool in situations like this.

Considering a scenario where future maintainers might need to modify these tests, it’s important to document our thought process here.

Please make a commit to add comments.

[moi15moi]

Please make a commit to add comments.

Done, let me know what you think.

[junkmd]

As the previous code demonstrates, QueryInterface and refcount tests can be performed with this package’s IUnknown.

To better reflect the accurate situation, I think a comments like “COM interfaces can use AddRef, Release, and QueryInterface inherited from IUnknown” would be more appropriate.