/// <summary>
/// A very naive version of property-based testing API.
/// </summary>
/// <remarks>
/// This implementation may be moved to a proper property-based testing framework like FsCheck.
/// </remarks>
private static void TestProperty(Func <MachineId[], MachineIdCollection, bool> propertyChecker, [CallerMemberName] string operation = null)
{
const ushort maxMachineId = 2048;
const int count = 50;
var random = new Random();
// Explicitly validating the property for empty collection and the collection with 1 element.
validateProperty(0);
validateProperty(1);
for (int i = 0; i < count; i++)
{
var collectionLength = random.Next(count);
validateProperty(collectionLength);
}
void validateProperty(int collectionLength)
{
var arrayOfMachineIds = Enumerable.Range(1, collectionLength).Select(_ => new MachineId(random.Next(maxMachineId))).ToArray();
var machineIdCollection = arrayOfMachineIds.Length == 1 ? MachineIdCollection.Create(arrayOfMachineIds[0]) : MachineIdCollection.Create(arrayOfMachineIds);
Assert.True(propertyChecker(arrayOfMachineIds, machineIdCollection), $"The property '{operation}' is falsifiable.");
}
}
public void BinManagerExcludesMaster()
{
var amountMachines = 4;
var machineMappings = Enumerable.Range(0, amountMachines).Select(i => new MachineMapping(new MachineLocation(i.ToString()), new MachineId(i))).ToArray();
var masterMapping = machineMappings[0];
var clusterState = new ClusterState(machineMappings[0].Id, machineMappings)
{
EnableBinManagerUpdates = true
};
foreach (var mapping in machineMappings)
{
clusterState.AddMachine(mapping.Id, mapping.Location);
}
clusterState.SetMasterMachine(masterMapping.Location);
clusterState.InitializeBinManagerIfNeeded(locationsPerBin: amountMachines, _clock, expiryTime: TimeSpan.Zero);
var binMappings = clusterState.GetBinMappings().ThrowIfFailure();
foreach (var binMapping in binMappings)
{
// Master should not be there
binMapping.Length.Should().Be(amountMachines - 1);
binMapping.Should().NotContain(masterMapping.Id);
}
// Make sure this stays true after updates
var inactiveMachines = new BitMachineIdSet(new byte[amountMachines], 0);
inactiveMachines = inactiveMachines.SetExistenceBits(MachineIdCollection.Create(machineMappings[1].Id), true);
clusterState.SetMachineStates(inactiveMachines).ShouldBeSuccess();
binMappings = clusterState.GetBinMappings().ThrowIfFailure();
foreach (var binMapping in binMappings)
{
// Master and inactive should not be there
binMapping.Length.Should().Be(amountMachines - 2);
binMapping.Should().NotContain(masterMapping.Id);
}
}
