Normalize imported hashes to lower case and default their null fields [patch]

ImageDescriber.Test/SearchTests.cs

@@ -55,6 +55,57 @@
 		CollectionAssert.AreEquivalent(expectedKeys, Program.Settings.Descriptions.Keys.ToArray());
 	}
 
+	[TestMethod]
+	public void MergeEntriesStoresAnUpperCaseHashAsTheLowerCaseHashScanLooksUp()
+	{
+		Program.Settings = new PersistentState();
+		string lowerHash = new('a', ImageHasher.HashLength);
+		string upperHash = lowerHash.ToUpperInvariant();
+		AbsoluteFilePath firstPath = Path.Combine(Path.GetTempPath(), "first.jpg").As<AbsoluteFilePath>();
+		AbsoluteFilePath secondPath = Path.Combine(Path.GetTempPath(), "second.jpg").As<AbsoluteFilePath>();
+
+		(int NewCount, int UpdatedCount, int SkippedCount) first = default;
+		(int NewCount, int UpdatedCount, int SkippedCount) second = default;
+		CaptureConsole(() => first = Import.MergeEntries([new() { Hash = upperHash, KnownPaths = [firstPath] }]));
+		CaptureConsole(() => second = Import.MergeEntries([new() { Hash = lowerHash, KnownPaths = [secondPath] }]));
+
+		Assert.AreEqual(1, first.NewCount);
+		Assert.AreEqual(1, second.UpdatedCount);
+		string[] expectedKeys = [lowerHash];
+		CollectionAssert.AreEquivalent(expectedKeys, Program.Settings.Descriptions.Keys.ToArray());
+		Assert.AreEqual(lowerHash, Program.Settings.Descriptions[lowerHash].Hash);
+		Assert.AreEqual(2, Program.Settings.Descriptions[lowerHash].KnownPaths.Count);
+	}
+
+	[TestMethod]
+	public void MergeEntriesRepairsNullFieldsSoSearchStatsAndExportStillRun()
+	{
+		Program.Settings = new PersistentState();
+		string hash = new('b', ImageHasher.HashLength);
+		List<ImageDescription> entries =
+		[
+			new()
+			{
+				Hash = hash,
+				Description = null!,
+				KnownPaths = null!,
+				SuggestedFileName = null!,
+				Model = null!,
+			},
+		];
+
+		CaptureConsole(() => Import.MergeEntries(entries));
+
+		ImageDescription stored = Program.Settings.Descriptions[hash];
+		Assert.IsNotNull(stored.Description);
+		Assert.IsNotNull(stored.KnownPaths);
+		Assert.IsNotNull(stored.SuggestedFileName);
+		Assert.IsNotNull(stored.Model);
+		CaptureConsole(() => new Search().Run(new Search { Query = "dog" }));
+		CaptureConsole(() => new Stats().Run(new Stats()));
+		StringAssert.Contains(Export.BuildCsv(Program.Settings.Descriptions.Values), hash);
+	}
+
 	[TestMethod]
 	public void IsValidHashAcceptsOnlySha256HexStrings()
 	{

ImageDescriber/Verbs/Import.cs

@@ -108,6 +108,11 @@ internal static (int NewCount, int UpdatedCount, int SkippedCount) MergeEntries(
 				continue;
 			}
 
+			// Scan looks hashes up as ComputeHash spells them, lower-case, and the store is keyed
+			// case-sensitively, so an upper-case hash from another tool would never match.
+			entry.Hash = entry.Hash.ToLowerInvariant();
+			RepairNullFields(entry);
+
 			if (Program.Settings.Descriptions.TryGetValue(entry.Hash, out ImageDescription? existing))
 			{
 				if (MergeKnownPaths(entry, existing))
@@ -129,6 +134,18 @@ internal static (int NewCount, int UpdatedCount, int SkippedCount) MergeEntries(
 		return (newCount, updatedCount, skippedCount);
 	}
 
+	/// <summary>
+	/// Defaults the fields a JSON import can set to null. Search, Stats, Export and Scan all
+	/// dereference them, so a stored null would make each of them throw on every later run.
+	/// </summary>
+	internal static void RepairNullFields(ImageDescription entry)
+	{
+		entry.KnownPaths = entry.KnownPaths is null ? [] : [.. entry.KnownPaths.Where(p => p is not null)];
+		entry.Description ??= string.Empty;
+		entry.SuggestedFileName ??= string.Empty.As<FileName>();
+		entry.Model ??= string.Empty.As<OllamaModelName>();
+	}
+
 	internal static bool MergeKnownPaths(ImageDescription source, ImageDescription target)
 	{
 		bool pathsAdded = false;