The Static Analysis tool detects whether async/await keywords are redundant.
You can omit async/await keywords if a method does not have the continuation code block. This allows you to avoid unnecessary delay in code execution. For example, you can return a Task from a method instead of the task's result if it is a Task type method.
async Task<string> DemoMethod(bool value, CancellationToken token) {
if (value)
return await Task.Run(() => "result1", token).ConfigureAwait(false); // CRR0030
return await Task.Run(() => "result2", token).ConfigureAwait(false); // CRR0030
}
Change the code above as follows to omit async/await:
Task<string> DemoMethod(bool value, CancellationToken token) {
if (value)
return Task.Run(() => "result1", token);
return Task.Run(() => "result2", token);
}
If your async method contains the continuation code you cannot omit async/await keywords:
async Task<string> DemoMethodAsync(bool value, CancellationToken token) {
if (value)
return await SomeMethodWhichReturnedTask().ConfigureAwait(false);
var someValue = await SomeAsyncMethod().ConfigureAwait(false);
if (someValue)
DoSomething();
return await AnotherMethodWhichReturnedTask().ConfigureAwait(false);
}
In the code above, when thread reaches await SomeAsyncMethod() this await makes the compiler to run operation on a new task and waits while this task is completed. Then, await causes thread to return and continue with execution. After the compiler finishes SomeAsyncMethod() it executes the DoSomething() method.