Testably · vbreuss · Apr 29, 2024 · Apr 21, 2024 · Apr 21, 2024 · Apr 21, 2024
diff --git a/Feature.Flags.props b/Feature.Flags.props
@@ -7,6 +7,7 @@
 		<IS_NET8_OR_HIGHER Condition="'$(TargetFramework)' == 'net8.0'">1</IS_NET8_OR_HIGHER>
 
 		<DefineConstants Condition="'$(TargetFramework)' == 'net48' OR '$(TargetFramework)' == 'netstandard2.0'">$(DefineConstants);NETFRAMEWORK</DefineConstants>
+		<DefineConstants Condition="'$(IS_NET21_OR_HIGHER)' == '1'">$(DefineConstants);CAN_SIMULATE_OTHER_OS</DefineConstants>
 		<DefineConstants Condition="'$(IS_NET21_OR_HIGHER)' == '1'">$(DefineConstants);FEATURE_FILESYSTEM_ASYNC</DefineConstants>
 		<DefineConstants Condition="'$(IS_NET21_OR_HIGHER)' == '1'">$(DefineConstants);FEATURE_FILESYSTEM_ENUMERATION_OPTIONS</DefineConstants>
 		<DefineConstants Condition="'$(IS_NET21_OR_HIGHER)' == '1'">$(DefineConstants);FEATURE_PATH_JOIN</DefineConstants>

diff --git a/README.md b/README.md
@@ -14,7 +14,7 @@ The testing helper also supports advanced scenarios like
 
 The companion projects [Testably.Abstractions.Compression](https://www.nuget.org/packages/Testably.Abstractions.Compression) and [Testably.Abstractions.AccessControl](https://www.nuget.org/packages/Testably.Abstractions.AccessControl) allow working with [Zip-Files](Examples/ZipFile/README.md) and [Access Control Lists](Examples/AccessControlLists/README.md) respectively.
 
-As the test suite runs both against the mocked and the real file system, the behaviour between the two is identical.
+As the test suite runs both against the mocked and the real file system, the behaviour between the two is identical and it also allows [simulating the file system on other operating systems](#simulating-other-operating-systems) (Linux, MacOS and Windows).
 
 In addition, the following interfaces are defined:
 - The `ITimeSystem` interface abstracts away time-related functionality:  
@@ -111,6 +111,25 @@ fileSystem.Initialize()
 	.WithFile("foo.txt").Which(f => f.HasStringContent("some file content"));
 ```
 
+### Simulating other operating systems
+
+The `MockFileSystem` can also simulate other operating systems than the one it is currently running on. This can be achieved, by providing the corresponding `SimulationMode` in the constructor:
+
+```csharp
+var linuxFileSystem = new MockFileSystem(o => o.SimulatingOperatingSystem(SimulationMode.Linux));
+// The `linuxFileSystem` now behaves like a Linux file system even under Windows:
+// - case-sensitive
+// - slash as directory separator
+
+var windowsFileSystem = new MockFileSystem(o => o.SimulatingOperatingSystem(SimulationMode.Windows));
+// The `windowsFileSystem` now behaves like a Windows file system even under Linux or MacOS:
+// - multiple drives
+// - case-insensitive
+// - backslash as directory separator
+```
+
+By running all tests against the real file system and the simulated under Linux, MacOS and Windows, the behaviour is consistent between the native and simulated mock file systems.
+
 ### Drive management
 ```csharp
 var fileSystem = new MockFileSystem();

diff --git a/Source/Testably.Abstractions.Testing/Helpers/Execute.cs b/Source/Testably.Abstractions.Testing/Helpers/Execute.cs
@@ -40,6 +40,9 @@ internal partial class Execute
 	/// </summary>
 	public StringComparison StringComparisonMode { get; }
 
+#if !CAN_SIMULATE_OTHER_OS
+	[Obsolete("Simulating other operating systems is not supported on .NET Framework")]
+#endif
 	internal Execute(MockFileSystem fileSystem, SimulationMode simulationMode)
 	{
 		IsLinux = simulationMode == SimulationMode.Linux;

diff --git a/Source/Testably.Abstractions.Testing/MockFileSystem.cs b/Source/Testably.Abstractions.Testing/MockFileSystem.cs
@@ -97,18 +97,29 @@ public MockFileSystem() : this(_ => { }) { }
 	/// <summary>
 	///     Initializes the <see cref="MockFileSystem" /> with the <paramref name="initializationCallback" />.
 	/// </summary>
-	internal MockFileSystem(Action<Initialization> initializationCallback)
+	public MockFileSystem(Action<Initialization> initializationCallback)
 	{
 		Initialization initialization = new();
 		initializationCallback(initialization);
 
 		SimulationMode = initialization.SimulationMode;
+#if CAN_SIMULATE_OTHER_OS
 		Execute = SimulationMode == SimulationMode.Native
 			? new Execute(this)
 			: new Execute(this, SimulationMode);
+#else
+		if (SimulationMode != SimulationMode.Native)
+		{
+			throw new NotSupportedException(
+				"Simulating other operating systems is not supported on .NET Framework");
+		}
+
+		Execute = new Execute(this);
+#endif
 		StatisticsRegistration = new FileSystemStatistics(this);
 		using IDisposable release = StatisticsRegistration.Ignore();
-		RandomSystem = new MockRandomSystem(initialization.RandomProvider ?? RandomProvider.Default());
+		RandomSystem =
+			new MockRandomSystem(initialization.RandomProvider ?? RandomProvider.Default());
 		TimeSystem = new MockTimeSystem(TimeProvider.Now());
 		_pathMock = new PathMock(this);
 		_storage = new InMemoryStorage(this);
@@ -225,7 +236,7 @@ private void InitializeFileSystem(Initialization initialization)
 	/// <summary>
 	///     The initialization options for the <see cref="MockFileSystem" />.
 	/// </summary>
-	internal class Initialization
+	public class Initialization
 	{
 		/// <summary>
 		///     The current directory.
@@ -242,10 +253,18 @@ internal class Initialization
 		/// </summary>
 		internal SimulationMode SimulationMode { get; private set; } = SimulationMode.Native;
 
+		internal Initialization()
+		{
+			// Avoid public constructor
+		}
+
 		/// <summary>
 		///     Specify the operating system that should be simulated.
 		/// </summary>
-		internal Initialization SimulatingOperatingSystem(SimulationMode simulationMode)
+#if !CAN_SIMULATE_OTHER_OS
+		[Obsolete("Simulating other operating systems is not supported on .NET Framework")]
+#endif
+		public Initialization SimulatingOperatingSystem(SimulationMode simulationMode)
 		{
 			SimulationMode = simulationMode;
 			return this;
@@ -254,7 +273,7 @@ internal Initialization SimulatingOperatingSystem(SimulationMode simulationMode)
 		/// <summary>
 		///     Use the provided <paramref name="path" /> as current directory.
 		/// </summary>
-		internal Initialization UseCurrentDirectory(string path)
+		public Initialization UseCurrentDirectory(string path)
 		{
 			CurrentDirectory = path;
 			return this;
@@ -263,7 +282,7 @@ internal Initialization UseCurrentDirectory(string path)
 		/// <summary>
 		///     Use <see cref="Directory.GetCurrentDirectory()" /> as current directory.
 		/// </summary>
-		internal Initialization UseCurrentDirectory()
+		public Initialization UseCurrentDirectory()
 		{
 			CurrentDirectory = System.IO.Directory.GetCurrentDirectory();
 			return this;
@@ -272,7 +291,7 @@ internal Initialization UseCurrentDirectory()
 		/// <summary>
 		///     Use the given <paramref name="randomProvider" /> for the <see cref="RandomSystem" />.
 		/// </summary>
-		internal Initialization UseRandomProvider(IRandomProvider randomProvider)
+		public Initialization UseRandomProvider(IRandomProvider randomProvider)
 		{
 			RandomProvider = randomProvider;
 			return this;

diff --git a/Source/Testably.Abstractions.Testing/Testably.Abstractions.Testing.csproj b/Source/Testably.Abstractions.Testing/Testably.Abstractions.Testing.csproj
@@ -21,9 +21,6 @@
 		<AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleToAttribute">
 			<_Parameter1>Testably.Abstractions.Testing.Tests</_Parameter1>
 		</AssemblyAttribute>
-		<AssemblyAttribute Include="System.Runtime.CompilerServices.InternalsVisibleToAttribute">
-			<_Parameter1>Testably.Abstractions.Tests</_Parameter1>
-		</AssemblyAttribute>
 	</ItemGroup>
 
 	<ItemGroup>

diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net6.0.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net6.0.txt
@@ -1,7 +1,6 @@
 [assembly: System.CLSCompliant(true)]
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/Testably/Testably.Abstractions.git")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Testing.Tests")]
-[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Tests")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v6.0", FrameworkDisplayName=".NET 6.0")]
 namespace Testably.Abstractions.Testing.FileSystem
 {
@@ -94,6 +93,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockFileSystem : System.IO.Abstractions.IFileSystem
     {
         public MockFileSystem() { }
+        public MockFileSystem(System.Action<Testably.Abstractions.Testing.MockFileSystem.Initialization> initializationCallback) { }
         public System.IO.Abstractions.IDirectory Directory { get; }
         public System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
@@ -112,6 +112,13 @@ namespace Testably.Abstractions.Testing
         public Testably.Abstractions.Testing.MockFileSystem WithAccessControlStrategy(Testably.Abstractions.Testing.FileSystem.IAccessControlStrategy accessControlStrategy) { }
         public Testably.Abstractions.Testing.MockFileSystem WithDrive(string? drive, System.Action<Testably.Abstractions.Testing.Storage.IStorageDrive>? driveCallback = null) { }
         public Testably.Abstractions.Testing.MockFileSystem WithSafeFileHandleStrategy(Testably.Abstractions.Testing.FileSystem.ISafeFileHandleStrategy safeFileHandleStrategy) { }
+        public class Initialization
+        {
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization SimulatingOperatingSystem(Testably.Abstractions.Testing.SimulationMode simulationMode) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory() { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory(string path) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseRandomProvider(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
+        }
     }
     public static class MockFileSystemExtensions
     {

diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net7.0.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net7.0.txt
@@ -1,7 +1,6 @@
 [assembly: System.CLSCompliant(true)]
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/Testably/Testably.Abstractions.git")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Testing.Tests")]
-[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Tests")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v7.0", FrameworkDisplayName=".NET 7.0")]
 namespace Testably.Abstractions.Testing.FileSystem
 {
@@ -94,6 +93,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockFileSystem : System.IO.Abstractions.IFileSystem
     {
         public MockFileSystem() { }
+        public MockFileSystem(System.Action<Testably.Abstractions.Testing.MockFileSystem.Initialization> initializationCallback) { }
         public System.IO.Abstractions.IDirectory Directory { get; }
         public System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
@@ -112,6 +112,13 @@ namespace Testably.Abstractions.Testing
         public Testably.Abstractions.Testing.MockFileSystem WithAccessControlStrategy(Testably.Abstractions.Testing.FileSystem.IAccessControlStrategy accessControlStrategy) { }
         public Testably.Abstractions.Testing.MockFileSystem WithDrive(string? drive, System.Action<Testably.Abstractions.Testing.Storage.IStorageDrive>? driveCallback = null) { }
         public Testably.Abstractions.Testing.MockFileSystem WithSafeFileHandleStrategy(Testably.Abstractions.Testing.FileSystem.ISafeFileHandleStrategy safeFileHandleStrategy) { }
+        public class Initialization
+        {
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization SimulatingOperatingSystem(Testably.Abstractions.Testing.SimulationMode simulationMode) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory() { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory(string path) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseRandomProvider(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
+        }
     }
     public static class MockFileSystemExtensions
     {

diff --git a/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net8.0.txt b/Tests/Api/Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_net8.0.txt
@@ -1,7 +1,6 @@
 [assembly: System.CLSCompliant(true)]
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/Testably/Testably.Abstractions.git")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Testing.Tests")]
-[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Tests")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v8.0", FrameworkDisplayName=".NET 8.0")]
 namespace Testably.Abstractions.Testing.FileSystem
 {
@@ -94,6 +93,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockFileSystem : System.IO.Abstractions.IFileSystem
     {
         public MockFileSystem() { }
+        public MockFileSystem(System.Action<Testably.Abstractions.Testing.MockFileSystem.Initialization> initializationCallback) { }
         public System.IO.Abstractions.IDirectory Directory { get; }
         public System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
@@ -112,6 +112,13 @@ namespace Testably.Abstractions.Testing
         public Testably.Abstractions.Testing.MockFileSystem WithAccessControlStrategy(Testably.Abstractions.Testing.FileSystem.IAccessControlStrategy accessControlStrategy) { }
         public Testably.Abstractions.Testing.MockFileSystem WithDrive(string? drive, System.Action<Testably.Abstractions.Testing.Storage.IStorageDrive>? driveCallback = null) { }
         public Testably.Abstractions.Testing.MockFileSystem WithSafeFileHandleStrategy(Testably.Abstractions.Testing.FileSystem.ISafeFileHandleStrategy safeFileHandleStrategy) { }
+        public class Initialization
+        {
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization SimulatingOperatingSystem(Testably.Abstractions.Testing.SimulationMode simulationMode) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory() { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory(string path) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseRandomProvider(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
+        }
     }
     public static class MockFileSystemExtensions
     {

diff --git a/...Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.0.txt b/...Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.0.txt
@@ -1,7 +1,6 @@
 [assembly: System.CLSCompliant(true)]
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/Testably/Testably.Abstractions.git")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Testing.Tests")]
-[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Tests")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.0", FrameworkDisplayName=".NET Standard 2.0")]
 namespace Testably.Abstractions.Testing.FileSystem
 {
@@ -92,6 +91,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockFileSystem : System.IO.Abstractions.IFileSystem
     {
         public MockFileSystem() { }
+        public MockFileSystem(System.Action<Testably.Abstractions.Testing.MockFileSystem.Initialization> initializationCallback) { }
         public System.IO.Abstractions.IDirectory Directory { get; }
         public System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
@@ -110,6 +110,14 @@ namespace Testably.Abstractions.Testing
         public Testably.Abstractions.Testing.MockFileSystem WithAccessControlStrategy(Testably.Abstractions.Testing.FileSystem.IAccessControlStrategy accessControlStrategy) { }
         public Testably.Abstractions.Testing.MockFileSystem WithDrive(string? drive, System.Action<Testably.Abstractions.Testing.Storage.IStorageDrive>? driveCallback = null) { }
         public Testably.Abstractions.Testing.MockFileSystem WithSafeFileHandleStrategy(Testably.Abstractions.Testing.FileSystem.ISafeFileHandleStrategy safeFileHandleStrategy) { }
+        public class Initialization
+        {
+            [System.Obsolete("Simulating other operating systems is not supported on .NET Framework")]
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization SimulatingOperatingSystem(Testably.Abstractions.Testing.SimulationMode simulationMode) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory() { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory(string path) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseRandomProvider(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
+        }
     }
     public static class MockFileSystemExtensions
     {

diff --git a/...Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.1.txt b/...Testably.Abstractions.Api.Tests/Expected/Testably.Abstractions.Testing_netstandard2.1.txt
@@ -1,7 +1,6 @@
 [assembly: System.CLSCompliant(true)]
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/Testably/Testably.Abstractions.git")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Testing.Tests")]
-[assembly: System.Runtime.CompilerServices.InternalsVisibleTo("Testably.Abstractions.Tests")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.1", FrameworkDisplayName=".NET Standard 2.1")]
 namespace Testably.Abstractions.Testing.FileSystem
 {
@@ -92,6 +91,7 @@ namespace Testably.Abstractions.Testing
     public sealed class MockFileSystem : System.IO.Abstractions.IFileSystem
     {
         public MockFileSystem() { }
+        public MockFileSystem(System.Action<Testably.Abstractions.Testing.MockFileSystem.Initialization> initializationCallback) { }
         public System.IO.Abstractions.IDirectory Directory { get; }
         public System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
@@ -110,6 +110,13 @@ namespace Testably.Abstractions.Testing
         public Testably.Abstractions.Testing.MockFileSystem WithAccessControlStrategy(Testably.Abstractions.Testing.FileSystem.IAccessControlStrategy accessControlStrategy) { }
         public Testably.Abstractions.Testing.MockFileSystem WithDrive(string? drive, System.Action<Testably.Abstractions.Testing.Storage.IStorageDrive>? driveCallback = null) { }
         public Testably.Abstractions.Testing.MockFileSystem WithSafeFileHandleStrategy(Testably.Abstractions.Testing.FileSystem.ISafeFileHandleStrategy safeFileHandleStrategy) { }
+        public class Initialization
+        {
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization SimulatingOperatingSystem(Testably.Abstractions.Testing.SimulationMode simulationMode) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory() { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseCurrentDirectory(string path) { }
+            public Testably.Abstractions.Testing.MockFileSystem.Initialization UseRandomProvider(Testably.Abstractions.Testing.RandomSystem.IRandomProvider randomProvider) { }
+        }
     }
     public static class MockFileSystemExtensions
     {