private async Task RunCacheAsync(FeatureFlagCacheService target, int refreshes, Action <int> callback = null)
{
var count = 0;
_options.RefreshInterval = TimeSpan.FromMilliseconds(100);
using (var cancellationTokenSource = new CancellationTokenSource())
{
_storage
.Setup(s => s.GetAsync())
.Callback(() =>
{
count++;
if (count == refreshes)
{
cancellationTokenSource.Cancel();
}
callback?.Invoke(count);
})
.ReturnsAsync(_latestFlags);
// Act
await target.RunAsync(cancellationTokenSource.Token);
}
}
public FactsBase()
{
_storage = new Mock <IFeatureFlagStorageService>();
_telemetry = new Mock <IFeatureFlagTelemetryService>();
_options = new FeatureFlagOptions();
_target = new FeatureFlagCacheService(
_storage.Object,
_options,
_telemetry.Object,
Mock.Of <ILogger <FeatureFlagCacheService> >());
_latestFlags = FeatureFlagStateBuilder
.Create()
.WithFeature("Foo", FeatureStatus.Enabled)
.Build();
_stalenessMetrics = new List <TimeSpan>();
_telemetry
.Setup(t => t.TrackFeatureFlagStaleness(It.IsAny <TimeSpan>()))
.Callback((TimeSpan staleness) =>
{
_stalenessMetrics.Add(staleness);
});
}
public async Task AllowsNullTelemetryService()
{
// Arrange
var target = new FeatureFlagCacheService(
_storage.Object,
_options,
telemetryService: null,
logger: Mock.Of <ILogger <FeatureFlagCacheService> >());
await RunCacheAsync(target, refreshes : 2);
// Act
var result = target.GetLatestFlagsOrNull();
// Assert
Assert.Same(_latestFlags, result);
_storage.Verify(s => s.GetAsync(), Times.Exactly(2));
}
