Get rid of xUnit fixtures

DiscordChatExporter.Cli.Tests/Utils/TempFile.cs

@@ -0,0 +1,45 @@
+using System;
+using System.IO;
+using System.Reflection;
+using PathEx = System.IO.Path;
+
+namespace DiscordChatExporter.Cli.Tests.Utils;
+
+internal partial class TempFile : IDisposable
+{
+    public string Path { get; }
+
+    public TempFile(string path) =>
+        Path = path;
+
+    public void Dispose()
+    {
+        try
+        {
+            File.Delete(Path);
+        }
+        catch (FileNotFoundException)
+        {
+        }
+    }
+}
+
+internal partial class TempFile
+{
+    public static TempFile Create()
+    {
+        var dirPath = PathEx.Combine(
+            PathEx.GetDirectoryName(Assembly.GetExecutingAssembly().Location) ?? Directory.GetCurrentDirectory(),
+            "Temp"
+        );
+
+        Directory.CreateDirectory(dirPath);
+
+        var filePath = PathEx.Combine(
+            dirPath,
+            Guid.NewGuid() + ".tmp"
+        );
+
+        return new TempFile(filePath);
+    }
+}