Disposable analyzers are not CompositeDisposable aware

[Evangelink]

Analyzer package

Microsoft.CodeAnalysis.FxCopAnalyzers

Package Version

v3.0.0-beta3.final (latest pre-release)

Diagnostic ID

Example: CA2213

But I assume some other analyzers might be wrong too.

Repro steps

public class MyObservableObject
{
	private readonly CompositeDisposable _disposables = new CompositeDisposable();
	private readonly Subject<bool> _canUndo;

	public MyObservableObject()
	{
		_canUndo = new Subject<bool>();
        _disposables.Add(_canUndo);

		// or

		_canUndo = new Subject<bool>().DisposeWith(_diposables);
	}
}

[Evangelink]

@mavasani I'd be happy to be able to have a chat with you some time about introducing some specific attributes that would help the analyzers to have a more accurate behavior. See #3174

[Evangelink]

@mavasani If we don't want to have a built-in "exception" for such case, would it be possible to at least create some kind of option where we could define a list of method doing some ownership transfer?

[Evangelink]

I think it would be handy to have something a little more fine-grained that Analyzer Configuration.md#configure-dispose-ownership-transfer-for-disposable-objects-passed-as-arguments-to-method-calls and instead have a list of methods/types/namespaces that are considered as transferring ownership.

@mavasani WDYT?

[mavasani]

I think we need to go with attribute annotation based solution here, similar to nullable attributes. editorconfig option might provide an alternate, but attributes are much more descriptive in source. @Evangelink would you like to come up with a proposal about set of attributes that we can use here?

[Evangelink]

I think we could have a look at this proposal: dotnet/runtime#29631

[manfred-brands]

There is an inconsistency between CA2000 and CA2213.

CA2000 recognizes "Collection Add methods" as ownership transfer.
See

CA2213 does not or do I need to say not anymore.
Our code use field = Disposer.Add(new DisposableClass()).
When compiling against version 6.0.0 of the analyzers, I get no warning from 7.0.0 onwards I do.