feat: implement GetRandomFileName for simulated Path (#569)

Add GetRandomFileName

Author: vbreuss

Source/Testably.Abstractions.Testing/Helpers/Execute.MacPath.cs

@@ -1,13 +1,9 @@
-using System.Linq;
-
-namespace Testably.Abstractions.Testing.Helpers;
+namespace Testably.Abstractions.Testing.Helpers;
 
 internal partial class Execute
 {
 	private sealed class MacPath(MockFileSystem fileSystem) : LinuxPath(fileSystem)
 	{
-		private readonly MockFileSystem _fileSystem = fileSystem;
-
 		private string? _tempPath;
 
 		/// <inheritdoc cref="IPath.GetTempPath()" />
@@ -16,12 +12,5 @@ public override string GetTempPath()
 			_tempPath ??= $"/var/folders/{RandomString(2)}/{RandomString(2)}_{RandomString(27)}/T/";
 			return _tempPath;
 		}
-
-		private string RandomString(int length)
-		{
-			const string chars = "abcdefghijklmnopqrstuvwxyz0123456789";
-			return new string(Enumerable.Repeat(chars, length)
-				.Select(s => s[_fileSystem.RandomSystem.Random.Shared.Next(s.Length)]).ToArray());
-		}
 	}
 }

Source/Testably.Abstractions.Testing/Helpers/Execute.SimulatedPath.cs

@@ -1,6 +1,6 @@
 using System;
-using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using System.Text;
 #if FEATURE_FILESYSTEM_NET7
 using Testably.Abstractions.Testing.Storage;
@@ -283,7 +283,7 @@ public ReadOnlySpan<char> GetPathRoot(ReadOnlySpan<char> path)
 
 		/// <inheritdoc cref="IPath.GetRandomFileName()" />
 		public string GetRandomFileName()
-			=> System.IO.Path.GetRandomFileName();
+			=> $"{RandomString(8)}.{RandomString(3)}";
 
 #if FEATURE_PATH_RELATIVE
 		/// <inheritdoc cref="IPath.GetRelativePath(string, string)" />
@@ -489,6 +489,13 @@ private string JoinInternal(string?[] paths)
 		}
 #endif
 
+		protected string RandomString(int length)
+		{
+			const string chars = "abcdefghijklmnopqrstuvwxyz0123456789";
+			return new string(Enumerable.Repeat(chars, length)
+				.Select(s => s[fileSystem.RandomSystem.Random.Shared.Next(s.Length)]).ToArray());
+		}
+
 		private bool TryGetExtensionIndex(string path, [NotNullWhen(true)] out int? dotIndex)
 		{
 			for (int i = path.Length - 1; i >= 0; i--)

Tests/Testably.Abstractions.Tests/FileSystem/Path/GetRandomFileNameTests.cs

@@ -8,6 +8,14 @@ public abstract partial class GetRandomFileNameTests<TFileSystem>
 	: FileSystemTestBase<TFileSystem>
 	where TFileSystem : IFileSystem
 {
+	[SkippableFact]
+	public void GetRandomFileName_ShouldMatch8Dot3Pattern()
+	{
+		string result = FileSystem.Path.GetRandomFileName();
+
+		result.Should().Match("????????.???");
+	}
+
 	[SkippableFact]
 	public void GetRandomFileName_ShouldReturnRandomFileNameWithExtension()
 	{