Preserve saved map names and Wolf Link UIDs during conversion

.github/workflows/tests.yml

@@ -0,0 +1,18 @@
+name: Tests
+
+on:
+  push:
+  pull_request:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: '6.0.x'
+      - run: dotnet test BotwSaveManager.Core.Tests/BotwSaveManager.Core.Tests.csproj --configuration Release

BotWSaveManager.sln

@@ -9,6 +9,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BotwSaveManager.Core", "Bot
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BotwSaveManager.Console", "BotwSaveManager.Console\BotwSaveManager.Console.csproj", "{5FD1DD50-4944-4614-A67D-84598C84DD16}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BotwSaveManager.Core.Tests", "BotwSaveManager.Core.Tests\BotwSaveManager.Core.Tests.csproj", "{16E414BF-49E8-4ACC-BF4D-9C3A47925EB1}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -27,6 +29,10 @@ Global
 		{5FD1DD50-4944-4614-A67D-84598C84DD16}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{5FD1DD50-4944-4614-A67D-84598C84DD16}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{5FD1DD50-4944-4614-A67D-84598C84DD16}.Release|Any CPU.Build.0 = Release|Any CPU
+		{16E414BF-49E8-4ACC-BF4D-9C3A47925EB1}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{16E414BF-49E8-4ACC-BF4D-9C3A47925EB1}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{16E414BF-49E8-4ACC-BF4D-9C3A47925EB1}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{16E414BF-49E8-4ACC-BF4D-9C3A47925EB1}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

BotwSaveManager.Core.Tests/BotwSaveManager.Core.Tests.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
+    <PackageReference Include="xunit" Version="2.6.6" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../BotwSaveManager.Core/BotwSaveManager.Core.csproj" />
+  </ItemGroup>
+
+</Project>

BotwSaveManager.Core.Tests/StringConversionTests.cs

@@ -0,0 +1,121 @@
+using System.Buffers.Binary;
+using System.Text;
+using BotwSaveManager.Core;
+using Xunit;
+
+namespace BotwSaveManager.Core.Tests;
+
+public class StringConversionTests
+{
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void ConvertPlatformPreservesSavedMapName(bool fromWiiU)
+    {
+        AssertStringConversion(0x0BEE9E46, "Z-9", 32, fromWiiU);
+    }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void ConvertPlatformPreservesWolfLinkDetectedUid(bool fromWiiU)
+    {
+        AssertStringConversion(0x1C10782F, "test-wolf-uid-0123456789", 64, fromWiiU);
+    }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public void ConvertPlatformStillPreservesHorseNames(bool fromWiiU)
+    {
+        AssertStringConversion(0x7B74E117, "Sage", 64, fromWiiU);
+    }
+
+    private static void AssertStringConversion(uint hash, string text, int capacity, bool fromWiiU)
+    {
+        // All input is generated here; no player saves or game assets are needed.
+        string root = Path.Combine(Path.GetTempPath(), "BotwSaveManager.Tests-" + Guid.NewGuid());
+        string source = Path.Combine(root, "source");
+        string output = Path.Combine(root, "output");
+        string roundTrip = Path.Combine(root, "round-trip");
+        Directory.CreateDirectory(Path.Combine(source, "0"));
+
+        try {
+            byte[] options = BuildOptions(fromWiiU);
+            byte[] original = BuildSave(hash, text, capacity, fromWiiU);
+            byte[] expected = BuildSave(hash, text, capacity, !fromWiiU);
+            byte[] photo = { 0xFF, 0xD8, 0xFF, 0xD9 };
+            File.WriteAllBytes(Path.Combine(source, "option.sav"), options);
+            File.WriteAllBytes(Path.Combine(source, "0", "game_data.sav"), original);
+            File.WriteAllBytes(Path.Combine(source, "0", "caption.jpg"), photo);
+
+            BotwSave save = new(source);
+            Assert.Equal(fromWiiU ? SaveType.WiiU : SaveType.Switch, save.SaveType);
+            save.ConvertPlatform(output);
+
+            // A round trip alone would also pass with the old, corrupting converter.
+            // Check the independently generated destination byte order on the first pass.
+            Assert.Equal(expected, File.ReadAllBytes(Path.Combine(output, "0", "game_data.sav")));
+            Assert.Equal(BuildOptions(!fromWiiU), File.ReadAllBytes(Path.Combine(output, "option.sav")));
+            Assert.Equal(fromWiiU ? SaveType.Switch : SaveType.WiiU, save.SaveType);
+            Assert.Equal(original, File.ReadAllBytes(Path.Combine(source, "0", "game_data.sav")));
+            Assert.Equal(options, File.ReadAllBytes(Path.Combine(source, "option.sav")));
+            Assert.Equal(photo, File.ReadAllBytes(Path.Combine(output, "0", "caption.jpg")));
+
+            BotwSave converted = new(output);
+            converted.ConvertPlatform(roundTrip);
+            Assert.Equal(original, File.ReadAllBytes(Path.Combine(roundTrip, "0", "game_data.sav")));
+            Assert.Equal(options, File.ReadAllBytes(Path.Combine(roundTrip, "option.sav")));
+        }
+        finally {
+            Directory.Delete(root, true);
+        }
+    }
+
+    private static byte[] BuildOptions(bool bigEndian)
+    {
+        using MemoryStream stream = new();
+        WriteHeader(stream, bigEndian);
+        WriteWord(stream, 0, bigEndian);
+        return stream.ToArray();
+    }
+
+    private static byte[] BuildSave(uint hash, string text, int capacity, bool bigEndian)
+    {
+        using MemoryStream stream = new();
+        WriteHeader(stream, bigEndian);
+
+        // Numeric entries before and after the string must still change byte order.
+        WriteWord(stream, 0x10203040, bigEndian);
+        WriteWord(stream, 0x12345678, bigEndian);
+        byte[] value = new byte[capacity];
+        Encoding.UTF8.GetBytes(text).CopyTo(value, 0);
+        for (int i = 0; i < value.Length; i += 4) {
+            WriteWord(stream, hash, bigEndian);
+            stream.Write(value, i, 4);
+        }
+        WriteWord(stream, 0x50607080, bigEndian);
+        WriteWord(stream, 0x87654321, bigEndian);
+        WriteWord(stream, 0, bigEndian);
+        return stream.ToArray();
+    }
+
+    private static void WriteHeader(Stream stream, bool bigEndian)
+    {
+        WriteWord(stream, 0x471B, bigEndian);
+        WriteWord(stream, 0xFFFFFFFF, bigEndian);
+        WriteWord(stream, 1, bigEndian);
+    }
+
+    private static void WriteWord(Stream stream, uint value, bool bigEndian)
+    {
+        Span<byte> bytes = stackalloc byte[4];
+        if (bigEndian) {
+            BinaryPrimitives.WriteUInt32BigEndian(bytes, value);
+        }
+        else {
+            BinaryPrimitives.WriteUInt32LittleEndian(bytes, value);
+        }
+        stream.Write(bytes);
+    }
+}

BotwSaveManager.Core/BotwSave.cs

@@ -44,7 +44,10 @@ public class BotwSave
             0xFD71ABCC, 0xCBC6B5E4, 0xE4B5C6CB, 0x2CADB0E7, 0xE7B0AD2C, 0xA6EB3EF4, 0xF43EEBA6,
             0x21D4CFFA, 0xFACFD421, 0x22A510D1, 0xD110A522, 0x98D10D53, 0x530DD198, 0x55A22047,
             0x4720A255, 0xE5A63A33, 0x333AA6E5, 0xBEC65061, 0x6150C6BE, 0xBC118370, 0x708311BC,
-            0x0E9D0E75, 0x750E9D0E
+            0x0E9D0E75, 0x750E9D0E,
+            // String field IDs in both byte orders: reverse the ID, not its UTF-8 value.
+            0x0BEE9E46, 0x469EEE0B, // PlayerSavePosMapName (string32)
+            0x1C10782F, 0x2F78101C  // WolfLink_TodayFirstDetectedUID (string64)
         };
 
         public SaveType SaveType { get; set; }