/// <summary>
/// Ensure the the environment variable MSBuildDisableFeaturesFromWave is set to a proper value.
/// </summary>
/// <returns> String representation of the set change wave. "999.999" if unset or invalid, and clamped if out of bounds. </returns>
internal static void ApplyChangeWave()
{
Version changeWave;
// If unset, enable all features.
if (DisabledWave.Length == 0 || DisabledWave.Equals(EnableAllFeatures, StringComparison.OrdinalIgnoreCase))
{
ConversionState = ChangeWaveConversionState.Valid;
DisabledWave = ChangeWaves.EnableAllFeatures;
return;
}
// If the version is of invalid format, log a warning and enable all features.
if (!Version.TryParse(DisabledWave, out changeWave))
{
ConversionState = ChangeWaveConversionState.InvalidFormat;
DisabledWave = ChangeWaves.EnableAllFeatures;
return;
}
// If the version is 999.999, we're done.
else if (changeWave == EnableAllFeaturesAsVersion)
{
ConversionState = ChangeWaveConversionState.Valid;
DisabledWave = changeWave.ToString();
return;
}
// If the version is out of rotation, log a warning and clamp the value.
else if (changeWave < LowestWaveAsVersion)
{
ConversionState = ChangeWaveConversionState.OutOfRotation;
DisabledWave = LowestWave;
return;
}
else if (changeWave > HighestWaveAsVersion)
{
ConversionState = ChangeWaveConversionState.OutOfRotation;
DisabledWave = HighestWave;
return;
}
// Ensure it's set to an existing version within the current rotation
if (!AllWavesAsVersion.Contains(changeWave))
{
foreach (Version wave in AllWavesAsVersion)
{
if (wave > changeWave)
{
ConversionState = ChangeWaveConversionState.Valid;
DisabledWave = wave.ToString();
return;
}
}
}
ConversionState = ChangeWaveConversionState.Valid;
DisabledWave = changeWave.ToString();
}
/// <summary>
/// Compares the passed wave to the MSBuildDisableFeaturesFromVersion environment variable.
/// </summary>
/// <param name="wave">The version to compare.</param>
/// <returns>A bool indicating whether the version is enabled.</returns>
public static bool AreFeaturesEnabled(Version wave)
{
if (_state == ChangeWaveConversionState.NotConvertedYet)
{
ApplyChangeWave();
}
// This is opt out behavior, all waves are enabled by default.
if (DisabledWave.Length == 0 || DisabledWave.Equals(EnableAllFeatures, StringComparison.OrdinalIgnoreCase))
{
return(true);
}
Version currentSetWave;
// If we can't parse the environment variable, default to enabling features.
if (!Version.TryParse(DisabledWave, out currentSetWave))
{
return(true);
}
return(wave < currentSetWave);
}
