From 3f82eed99136463845e2e3d8e0f5f11252fa7dab Mon Sep 17 00:00:00 2001
From: halgari <tbaldridge@gmail.com>
Date: Tue, 15 Oct 2024 12:19:08 -0600
Subject: [PATCH] Fixed a bug in the key prefix and added a test of failed
 migration (converting a URI to a ulong)

---
 .../Internals/KeyPrefix.cs                    |  2 +-
 .../Serializer.cs                             | 27 ++++++++++++-----
 .../MigrationTests.cs                         | 30 +++++++++++++++++++
 3 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/src/NexusMods.MnemonicDB.Abstractions/Internals/KeyPrefix.cs b/src/NexusMods.MnemonicDB.Abstractions/Internals/KeyPrefix.cs
index 7915700..fb1feac 100644
--- a/src/NexusMods.MnemonicDB.Abstractions/Internals/KeyPrefix.cs
+++ b/src/NexusMods.MnemonicDB.Abstractions/Internals/KeyPrefix.cs
@@ -95,7 +95,7 @@ public bool IsRetract
     public ValueTag ValueTag
     {
         get => (ValueTag)((_lower >> 1) & 0x7F);
-        init => _lower = (_lower & 0xFF00000000000001) | ((ulong)value << 1);
+        init => _lower = (_lower & 0xFFFFFFFFFFFFFF01) | ((ulong)value << 1);
     }
 
     /// <summary>
diff --git a/src/NexusMods.MnemonicDB.Abstractions/Serializer.cs b/src/NexusMods.MnemonicDB.Abstractions/Serializer.cs
index bcf67a2..ce331bb 100644
--- a/src/NexusMods.MnemonicDB.Abstractions/Serializer.cs
+++ b/src/NexusMods.MnemonicDB.Abstractions/Serializer.cs
@@ -403,14 +403,27 @@ public static void ConvertValue<TWriter>(this ValueTag srcTag, ReadOnlySpan<byte
         where TWriter : IBufferWriter<byte>
     {
 
-        switch (srcTag, destTag)
+        try
         {
-            case (ValueTag.UInt8, ValueTag.UInt16):
-                WriteUnmanaged((ushort)MemoryMarshal.Read<byte>(srcSpan), destWriter);
-                break;
-            
-            default:
-                throw new NotSupportedException("Conversion not supported from " + srcTag + " to " + destTag);
+            switch (srcTag, destTag)
+            {
+                case (ValueTag.UInt8, ValueTag.UInt16):
+                    WriteUnmanaged((ushort)MemoryMarshal.Read<byte>(srcSpan), destWriter);
+                    break;
+                case (ValueTag.Utf8, ValueTag.UInt64):
+                {
+                    var val = srcTag.Read<string>(srcSpan);
+                    WriteUnmanaged(Convert.ToUInt64(val), destWriter);
+                    break;
+                }
+
+                default:
+                    throw new NotSupportedException("Conversion not supported from " + srcTag + " to " + destTag);
+            }
+        }
+        catch (Exception e)
+        {
+            throw new InvalidOperationException($"Failed to convert ({srcTag.Read<object>(srcSpan)}) value from " + srcTag + " to " + destTag, e);
         }
     }
 
diff --git a/tests/NexusMods.MnemonicDB.Tests/MigrationTests.cs b/tests/NexusMods.MnemonicDB.Tests/MigrationTests.cs
index a3649eb..b6e2c78 100644
--- a/tests/NexusMods.MnemonicDB.Tests/MigrationTests.cs
+++ b/tests/NexusMods.MnemonicDB.Tests/MigrationTests.cs
@@ -95,4 +95,34 @@ public async Task CanRemoveIndex()
         Action act = () => Connection.Db.Datoms(Mod.Source, new Uri("http://mod0.com")).ToArray();
         act.Should().Throw<InvalidOperationException>();
     }
+
+    [Fact]
+    public async Task CanConvertValues()
+    {
+        await AddData();
+
+        var cache = Connection.AttributeCache;
+        var aid = cache.GetAttributeId(Mod.Description.Id);
+        cache.IsIndexed(aid).Should().BeFalse();
+        
+        var withIndex = new ULongAttribute(Mod.Description.Id.Namespace, Mod.Description.Id.Name) { IsIndexed = true, IsOptional = false };
+        var prevTxId = Connection.Db.BasisTxId;
+
+        await Connection.UpdateSchema(withIndex);
+
+        Connection.Db.BasisTxId.Value.Should().Be(prevTxId.Value + 1);
+        cache.IsIndexed(cache.GetAttributeId(Mod.Description.Id)).Should().BeTrue();
+        
+        var foundByDocs = Connection.Db.Datoms(withIndex, 0UL).ToArray();
+        foundByDocs.Length.Should().Be(10);
+    }
+
+    [Fact]
+    public async Task ConvertingValuesIncorrectlyFails()
+    {
+        await AddData();
+        var withIndex = new ULongAttribute(Mod.Source.Id.Namespace, Mod.Source.Id.Name) { IsIndexed = true, IsOptional = false };
+        var act = async () => await Connection.UpdateSchema(withIndex);
+        await act.Should().ThrowAsync<InvalidOperationException>("Converting values for attribute Mod.Source from String to ULong where the source is a URI should fail");
+    }
 }