Should I worry about “This async method lacks 'await' operators and will run synchronously” warning

Question

I have a interface which exposes some async methods. More specifically it has methods defined which return either Task or Task. I am using the async/await keywords.

Answer 1

Michael Liu answered well your question about how you can avoid the warning: by returning Task.FromResult.

I'm going to answer the "Should I worry about the warning" part of your question.

The answer is Yes!

The reason for this is that the warning frequently results when you call a method that returns Task inside of an async method without the await operator. I just fixed a concurrency bug that happened because I invoked an operation in Entity Framework without awaiting the previous operation.

If you can meticulously write your code to avoid compiler warnings, then when there is a warning, it will stand out like a sore thumb. I could have avoided several hours of debugging.