Calling Wait() (or any variation) instead of awaiting a task

[BillWagner]

Tasks should not block. Instead, they should be awaited so that execution can continue.

[sharwell]

Definitely an item of interest.

My instinct is this would be a warning when it occurs within an async method, and an information-level diagnostic elsewhere.

Checking the Result property can do this as well, but it will be very hard to know whether a particular access to the Result property is problematic or not. I'll have to think much more about this.

[tugberkugurlu]

This should never give a diagnostic message as there are quite a lot of places where you cannot run asyncronous code such as ASP.NET MVC child actions, Main method, etc.

[sharwell]

@tugberkugurlu What about within the body of an async method?

[tugberkugurlu]

@sharwell I think that case qualifies as a legit use of this analyzer.

[tmaczynski]

I will gladly implement initial version of this diagnostic once #50 is reviewed. I think that thanks to stuff I learned working on #50, coding this diagnostic should be quite simple.

To be on a safe side, I will find all usages of Wait() in async methods, async anonymous functions or async anonymous methods. Later, we can iterate and refine this diagnostic.

[AArnott]

Our VSTHRD002 analyzer does this.