Fixie Convention - Retry on SQL Timeouts

Retry.cs

public class IntegrationTestConvention : Convention
{
    public IntegrationTestConvention()
    {
        Classes
            .NameEndsWith("Tests");

        Methods
            .Where(method => method.IsVoid() || method.IsAsync());

        CaseExecution
            .Wrap<RetryOnSqlTimeout>();
    }
}

public class RetryOnSqlTimeout : CaseBehavior
{
    public void Execute(Case @case, Action execute)
    {
        execute(); //Run the test for the first time.

        if (@case.Exceptions.Count == 1)
        {
            var exception = @case.Exceptions.Single();

            var sqlException = exception as SqlException;

            const int timeout = -2;
            if (sqlException != null && sqlException.Number == timeout)
            {
                @case.ClearExceptions();

                execute(); //Run the test for the second time.

                //You might instead do this check/clear/retry in a loop,
                //but even then you'd want to bail out after a few
                //consecutive failures.
            }
        }
    }
}

public class LongRunningQueryTests
{
    public void AlwaysPasses()
    {
        Console.WriteLine("AlwaysPasses");
    }

    public void AlwaysFails()
    {
        Console.WriteLine("AlwaysFails");
        throw new NotSupportedException();
    }

    static bool hasTimedOutAlready = false;
    public void TimesOutOnFirstTry()
    {
        Console.WriteLine("TimesOutOnFirstTry");

        if (hasTimedOutAlready)
            return;

        hasTimedOutAlready = true;
        throw new SqlException(-2);
    }
}

/// <summary>
/// The real SqlException class can't be constructed directly.
/// For the sake of the example, here we imitate the part that matters.
/// SqlException's Number property indicates the specific problem.
/// -2 indicates timeout.
/// </summary>
public class SqlException : Exception
{
    public int Number { get; private set; }

    public SqlException(int number)
    {
        Number = number;
    }
}