Fix string conversion of Microsoft.TestPlatform.Extensions.TrxLogger.ObjectMode.TestOutcome

[MarcoRossignoli]

By design we cannot have a "correct" value from a string conversion from enum for the same underlying value.
The behavior changed since 7.0 and now the runtime is returning Min and not Error

fixed #4227

[MarcoRossignoli]

using System.ComponentModel;

TestOutcome value = TestOutcome.Error;
Type valueType = value.GetType();
TypeConverter convert = TypeDescriptor.GetConverter(valueType);
var valueToSave = convert.ConvertToInvariantString(value);
Console.WriteLine(valueToSave);

internal enum TestOutcome
{
    /// <summary>
    /// There was a system error while we were trying to execute a test.
    /// </summary>
    Error,

    /// <summary>
    /// Test was executed, but there were issues.
    /// Issues may involve exceptions or failed assertions.
    /// </summary>
    Failed,

    /// <summary>
    /// The test timed out
    /// </summary>
    Timeout,

    /// <summary>
    /// Test was aborted.
    /// This was not caused by a user gesture, but rather by a framework decision.
    /// </summary>
    Aborted,

    /// <summary>
    /// Test has completed, but we can't say if it passed or failed.
    /// May be used for aborted tests...
    /// </summary>
    Inconclusive,

    /// <summary>
    /// Test was executed w/o any issues, but run was aborted.
    /// </summary>
    PassedButRunAborted,

    /// <summary>
    /// Test had it chance for been executed but was not, as ITestElement.IsRunnable == false.
    /// </summary>
    NotRunnable,

    /// <summary>
    /// Test was not executed.
    /// This was caused by a user gesture - e.g. user hit stop button.
    /// </summary>
    NotExecuted,

    /// <summary>
    /// Test run was disconnected before it finished running.
    /// </summary>
    Disconnected,

    /// <summary>
    /// To be used by Run level results.
    /// This is not a failure.
    /// </summary>
    Warning,

    /// <summary>
    /// Test was executed w/o any issues.
    /// </summary>
    Passed,

    /// <summary>
    /// Test has completed, but there is no qualitative measure of completeness.
    /// </summary>
    Completed,

    /// <summary>
    /// Test is currently executing.
    /// </summary>
    InProgress,

    /// <summary>
    /// Test is in the execution queue, was not started yet.
    /// </summary>
    Pending,

    /// <summary>
    /// The min value of this enum
    /// </summary>
    Min = Error,

    /// <summary>
    /// The max value of this enum
    /// </summary>
    Max = Pending
}

net6.0 output Error
net7.0 output Min

[Evangelink]

I am assuming this isn't tested as we didn't get any failure. Could we add a test?

[MarcoRossignoli]

We found out that the enum is internal and Min/Max are not used and we have only 1 friend, the unit test project, should be safe remove.