VSTHRD104.md

VSTHRD104 Offer async option

When a publicly accessible method uses JoinableTaskFactory.Run, there should be another way to access the async behavior without synchronously blocking the thread so that an async caller can be async throughout.

This rule encourages this pattern by recognizing when some method Foo exists and calls JoinableTaskFactory.Run that there is also a method FooAsync. The recommended pattern then is for Foo to call FooAsync from the delegate passed to JoinableTaskFactory.Run so that the implementation only need be written once.

Examples of patterns that are flagged by this analyzer

public void Foo() {
    this.joinableTaskFactory.Run(async delegate {
        await Task.Yield();
    });
}

Solution

Add a FooAsync method, and (optionally) call it from the Foo method:

public void Foo() {
    this.joinableTaskFactory.Run(async delegate {
        await FooAsync();
    });
}

public async Task FooAsync() {
    await Task.Yield();
}