CA2025 Do not pass IDisposable instances into unawaited tasks

[steveberdy]

Unawaited tasks that use IDisposable instances may use those instances long after they have been disposed. Ensure tasks using those instances are completed before the instances are disposed.

Example case where the analyzer fires:

public static Task Case1Async()
{
    using (var ms = new MemoryStream())
    {
        return DoAsync(ms);
    }
}

The analyzer can detect more advanced use cases and choose not to fire, such as when the task is referenced and awaited later before its disposable arguments are disposed:

public Task Case2Async()
{
    var stream = new MemoryStream();
    var reader = new StreamReader(stream);

    var t = AnotherTaskAsync(stream, reader);
    // Some code here...
    await t.ConfigureAwait(false);
    // Dispose reader and stream...
}

Fixes dotnet/runtime#78394

[codecov]

Codecov Report

Attention: Patch coverage is 98.60051% with 11 lines in your changes missing coverage. Please review.

Project coverage is 96.51%. Comparing base (3746107) to head (0d076be).

Additional details and impacted files

@@           Coverage Diff            @@
##             main    #7549    +/-   ##
========================================
  Coverage   96.50%   96.51%            
========================================
  Files        1452     1454     +2     
  Lines      347575   348361   +786     
  Branches    11418    11443    +25     
========================================
+ Hits       335436   336207   +771     
- Misses       9244     9252     +8     
- Partials     2895     2902     +7