Split Settings into model, serializer, paths and store

698 lines did all of it at once. The mutable CaptureFromUi callback becomes an
ISettingsCapture the settings view implements.

StarterNG.Tests/Fakes/FakeEnvironment.cs

@@ -0,0 +1,34 @@
+using StarterNG.Application.Abstractions;
+
+namespace StarterNG.Tests.Fakes;
+
+/// <summary>A host machine described inline: platform, home folder, env vars.</summary>
+public sealed class FakeEnvironment : IEnvironment
+{
+    private readonly Dictionary<string, string> _variables = new(StringComparer.Ordinal);
+
+    public bool IsWindows { get; set; }
+
+    public bool IsLinux { get; set; } = true;
+
+    public bool IsMacOS { get; set; }
+
+    public string BaseDirectory { get; set; } = Path.Combine("game");
+
+    public string? GetVariable(string name) => _variables.TryGetValue(name, out var value) ? value : null;
+
+    public FakeEnvironment With(string name, string value)
+    {
+        _variables[name] = value;
+        return this;
+    }
+
+    /// <summary>Switches the fake to Windows, with an APPDATA folder.</summary>
+    public FakeEnvironment AsWindows(string appData = "C:/Users/kolejarz/AppData/Roaming")
+    {
+        IsWindows = true;
+        IsLinux = false;
+        IsMacOS = false;
+        return With("APPDATA", appData);
+    }
+}

StarterNG.Tests/Fakes/InMemoryFileSystem.cs

@@ -15,6 +15,7 @@ public sealed class InMemoryFileSystem : IFileSystem
 {
     private readonly Dictionary<string, byte[]> _files = new(StringComparer.OrdinalIgnoreCase);
     private readonly HashSet<string> _directories = new(StringComparer.OrdinalIgnoreCase);
+    private readonly HashSet<string> _executable = new(StringComparer.OrdinalIgnoreCase);
 
     public DateTime LastWriteTimeUtc { get; set; } = new(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc);
 
@@ -115,6 +116,16 @@ public sealed class InMemoryFileSystem : IFileSystem
 
     public DateTime GetLastWriteTimeUtc(string path) => LastWriteTimeUtc;
 
+    /// <summary>Files added through <see cref="WithExecutable"/> carry the execute bit.</summary>
+    public bool IsExecutable(string path) => _executable.Contains(Normalize(path));
+
+    public InMemoryFileSystem WithExecutable(string path, string contents = "\u007fELF")
+    {
+        WithFile(path, contents);
+        _executable.Add(Normalize(path));
+        return this;
+    }
+
     private byte[] Bytes(string path) =>
         _files.TryGetValue(Normalize(path), out var bytes)
             ? bytes

StarterNG.Tests/Fakes/TestInstallation.cs

@@ -1,6 +1,7 @@
 using StarterNG.Application;
 using StarterNG.Infrastructure.Adapters;
 using StarterNG.Infrastructure.Sceneries;
+using StarterNG.Infrastructure.Settings;
 using StarterNG.Infrastructure.Vehicles;
 
 namespace StarterNG.Tests.Fakes;
@@ -28,6 +29,11 @@ public sealed class TestInstallation
         Sceneries = new SceneryRepository(Files, Paths, Log, new SceneryParser(Clock, Random));
         MissingAssets = new MissingAssetScanner(Files, Paths);
         Library = new GameLibrary(Vehicles, Sceneries, MiniTextures, Physics, Log);
+
+        Environment = new FakeEnvironment();
+        SettingsPaths = new SettingsPaths(Environment, Paths);
+        Executables = new ExecutableLocator(Files, Paths, Environment, Log);
+        SettingsStore = new SettingsStore(Files, Clock, Log, SettingsPaths, new SettingsSerializer(), Executables);
     }
 
     public InMemoryFileSystem Files { get; }
@@ -42,6 +48,10 @@ public sealed class TestInstallation
     public SceneryRepository Sceneries { get; }
     public MissingAssetScanner MissingAssets { get; }
     public GameLibrary Library { get; }
+    public FakeEnvironment Environment { get; }
+    public SettingsPaths SettingsPaths { get; }
+    public ExecutableLocator Executables { get; }
+    public SettingsStore SettingsStore { get; }
 
     /// <summary>Path of a file inside the fake installation.</summary>
     public static string At(params string[] segments) => Path.Combine(new[] { Root }.Concat(segments).ToArray());