save progress

src/Scanner/__Libraries/StellaOps.Scanner.Storage.Oci/SlicePullService.cs

@@ -61,6 +61,7 @@ public sealed class SlicePullService : IDisposable
     private readonly OciRegistryAuthorization _authorization;
     private readonly SlicePullOptions _options;
     private readonly ILogger<SlicePullService> _logger;
+    private readonly TimeProvider _timeProvider;
     private readonly Dictionary<string, CachedSlice> _cache = new(StringComparer.Ordinal);
     private readonly Lock _cacheLock = new();
 
@@ -70,12 +71,14 @@ public sealed class SlicePullService : IDisposable
         HttpClient httpClient,
         OciRegistryAuthorization authorization,
         SlicePullOptions? options = null,
-        ILogger<SlicePullService>? logger = null)
+        ILogger<SlicePullService>? logger = null,
+        TimeProvider? timeProvider = null)
     {
         _httpClient = httpClient ?? throw new ArgumentNullException(nameof(httpClient));
         _authorization = authorization ?? throw new ArgumentNullException(nameof(authorization));
         _options = options ?? new SlicePullOptions();
         _logger = logger ?? Microsoft.Extensions.Logging.Abstractions.NullLogger<SlicePullService>.Instance;
+        _timeProvider = timeProvider ?? TimeProvider.System;
         _httpClient.Timeout = _options.RequestTimeout;
     }
 
@@ -211,7 +214,7 @@ public sealed class SlicePullService : IDisposable
             var dsseLayer = manifest.Layers?.FirstOrDefault(l =>
                 l.MediaType == OciMediaTypes.DsseEnvelope);
 
-            if (dsseLayer != null && _options.VerifySignature)
+            if (dsseLayer?.Digest != null && _options.VerifySignature)
             {
                 var dsseResult = await FetchAndVerifyDsseAsync(reference, dsseLayer.Digest, sliceBytes, cancellationToken)
                     .ConfigureAwait(false);
@@ -227,7 +230,7 @@ public sealed class SlicePullService : IDisposable
                     SliceData = sliceData,
                     DsseEnvelope = dsseEnvelope,
                     SignatureVerified = signatureVerified,
-                    ExpiresAt = DateTimeOffset.UtcNow.Add(_options.CacheTtl)
+                    ExpiresAt = _timeProvider.GetUtcNow().Add(_options.CacheTtl)
                 });
             }
 
@@ -411,7 +414,7 @@ public sealed class SlicePullService : IDisposable
         {
             if (_cache.TryGetValue(key, out cached))
             {
-                if (cached.ExpiresAt > DateTimeOffset.UtcNow)
+                if (cached.ExpiresAt > _timeProvider.GetUtcNow())
                 {
                     return true;
                 }