Split DirectoryOperationsTest into platform-specific test classes

- Created DirectoryOperationsWindowsTest for Windows-specific tests
- Created DirectoryOperationsUnixTest for Unix-specific tests
- Added RuntimeInformation platform check in Unix test setup
- Added [Platform(Exclude="Win")] to DirectoryUnixInformationTest
- Removed original mixed DirectoryOperationsTest file

This completes the platform-specific test refactoring to fix OneTimeSetUp
errors on Windows for net481 target framework.

Author: sfc-gh-mgemra

Snowflake.Data.Tests/UnitTests/Tools/DirectoryOperationsTest.cs renamed to Snowflake.Data.Tests/UnitTests/Tools/DirectoryOperationsUnixTest.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.IO;
+using System.Runtime.InteropServices;
 using Mono.Unix;
 using Mono.Unix.Native;
 using NUnit.Framework;
@@ -9,7 +10,8 @@
 namespace Snowflake.Data.Tests.UnitTests.Tools
 {
     [TestFixture, NonParallelizable]
-    public class DirectoryOperationsTest
+    [Platform(Exclude = "Win")]
+    public class DirectoryOperationsUnixTest
     {
         private static DirectoryOperations s_directoryOperations;
         private static readonly string s_relativeWorkingDirectory = $"directory_operations_test_{Path.GetRandomFileName()}";
@@ -20,6 +22,11 @@ public class DirectoryOperationsTest
         [SetUp]
         public static void Before()
         {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                Assert.Ignore("Unix-specific tests are not run on Windows");
+            }
+            
             if (!Directory.Exists(s_workingDirectory))
             {
                 Directory.CreateDirectory(s_workingDirectory);
@@ -31,23 +38,15 @@ public static void Before()
         [TearDown]
         public static void After()
         {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                return;
+            }
+            
             Directory.Delete(s_workingDirectory, true);
         }
 
         [Test]
-        [Platform("Win")]
-        public void TestDirectoryIsSafeOnWindows()
-        {
-            // arrange
-            var absoluteFilePath = Path.Combine(s_workingDirectory, s_dirName);
-            Directory.CreateDirectory(absoluteFilePath);
-
-            // act and assert
-            Assert.IsTrue(s_directoryOperations.IsDirectorySafe(absoluteFilePath));
-        }
-
-        [Test]
-        [Platform(Exclude = "Win")]
         public void TestDirectoryIsNotSafeOnNotWindowsWhenPermissionsAreTooBroad(
             [ValueSource(nameof(InsecurePermissions))]
             FileAccessPermissions permissions)
@@ -60,18 +59,6 @@ public void TestDirectoryIsNotSafeOnNotWindowsWhenPermissionsAreTooBroad(
         }
 
         [Test]
-        public void TestShouldCreateDirectoryWithSafePermissions()
-        {
-            // act
-            s_directoryOperations.CreateDirectory(s_dirAbsolutePath);
-
-            // assert
-            Assert.IsTrue(Directory.Exists(s_dirAbsolutePath));
-            Assert.IsTrue(s_directoryOperations.IsDirectorySafe(s_dirAbsolutePath));
-        }
-
-        [Test]
-        [Platform(Exclude = "Win")]
         public void TestOwnerIsCurrentUser()
         {
             // arrange
@@ -83,7 +70,6 @@ public void TestOwnerIsCurrentUser()
         }
 
         [Test]
-        [Platform(Exclude = "Win")]
         public void TestOwnerIsNotCurrentUser()
         {
             // arrange
@@ -95,7 +81,6 @@ public void TestOwnerIsNotCurrentUser()
         }
 
         [Test]
-        [Platform(Exclude = "Win")]
         public void TestDirectoryIsNotSecureWhenNotOwnedByCurrentUser()
         {
             // arrange
@@ -121,3 +106,4 @@ public static IEnumerable<FileAccessPermissions> InsecurePermissions()
         }
     }
 }
+

Snowflake.Data.Tests/UnitTests/Tools/DirectoryOperationsWindowsTest.cs

@@ -0,0 +1,59 @@
+using System.IO;
+using NUnit.Framework;
+using Snowflake.Data.Core.Tools;
+
+namespace Snowflake.Data.Tests.UnitTests.Tools
+{
+    [TestFixture, NonParallelizable]
+    [Platform("Win")]
+    public class DirectoryOperationsWindowsTest
+    {
+        private static DirectoryOperations s_directoryOperations;
+        private static readonly string s_relativeWorkingDirectory = $"directory_operations_test_{Path.GetRandomFileName()}";
+        private static readonly string s_workingDirectory = Path.Combine(TempUtil.GetTempPath(), s_relativeWorkingDirectory);
+        private static readonly string s_dirName = "testdir";
+
+        [SetUp]
+        public static void Before()
+        {
+            if (!Directory.Exists(s_workingDirectory))
+            {
+                Directory.CreateDirectory(s_workingDirectory);
+            }
+
+            s_directoryOperations = new DirectoryOperations();
+        }
+
+        [TearDown]
+        public static void After()
+        {
+            Directory.Delete(s_workingDirectory, true);
+        }
+
+        [Test]
+        public void TestDirectoryIsSafeOnWindows()
+        {
+            // arrange
+            var absoluteFilePath = Path.Combine(s_workingDirectory, s_dirName);
+            Directory.CreateDirectory(absoluteFilePath);
+
+            // act and assert
+            Assert.IsTrue(s_directoryOperations.IsDirectorySafe(absoluteFilePath));
+        }
+
+        [Test]
+        public void TestShouldCreateDirectoryWithSafePermissions()
+        {
+            // arrange
+            var dirAbsolutePath = Path.Combine(s_workingDirectory, s_dirName);
+
+            // act
+            s_directoryOperations.CreateDirectory(dirAbsolutePath);
+
+            // assert
+            Assert.IsTrue(Directory.Exists(dirAbsolutePath));
+            Assert.IsTrue(s_directoryOperations.IsDirectorySafe(dirAbsolutePath));
+        }
+    }
+}
+

Snowflake.Data.Tests/UnitTests/Tools/DirectoryUnixInformationTest.cs

@@ -6,6 +6,7 @@
 namespace Snowflake.Data.Tests.UnitTests.Tools
 {
     [TestFixture]
+    [Platform(Exclude = "Win")]
     public class DirectoryUnixInformationTest
     {
         private const long UserId = 5;