Use shared test collection fixture for extractor tests

Replaced individual class fixtures with a shared ExtractorTestCollection using Xunit's [CollectionDefinition] and ICollectionFixture<BaseExtractorTestClass>. This ensures all extractor test classes share a single fixture instance, preventing race conditions and premature deletion of shared resources during parallel test execution.

Author: gfs

RecursiveExtractor.Tests/ExtractorTests/DisposeBehaviorTests.cs

@@ -8,7 +8,8 @@
 
 namespace RecursiveExtractor.Tests.ExtractorTests;
 
-public class DisposeBehaviorTests : IClassFixture<BaseExtractorTestClass>
+[Collection(ExtractorTestCollection.Name)]
+public class DisposeBehaviorTests
 {
     [Theory]
     [InlineData("TestData.7z", 3, false)]

RecursiveExtractor.Tests/ExtractorTests/EncryptedArchiveTests.cs

@@ -8,7 +8,8 @@
 
 namespace RecursiveExtractor.Tests.ExtractorTests;
 
-public class EncryptedArchiveTests : IClassFixture<BaseExtractorTestClass>
+[Collection(ExtractorTestCollection.Name)]
+public class EncryptedArchiveTests
 {
     [Theory]
     [InlineData("TestDataEncryptedZipCrypto.zip")]

RecursiveExtractor.Tests/ExtractorTests/ExpectedNumFilesTests.cs

@@ -11,7 +11,8 @@
 
 namespace RecursiveExtractor.Tests.ExtractorTests
 {
-    public class ExpectedNumFilesTests : IClassFixture<BaseExtractorTestClass>
+    [Collection(ExtractorTestCollection.Name)]
+    public class ExpectedNumFilesTests
     {
 
         /// <summary>

RecursiveExtractor.Tests/ExtractorTests/ExtractorTestCollection.cs

@@ -0,0 +1,16 @@
+using Xunit;
+
+namespace RecursiveExtractor.Tests.ExtractorTests;
+
+/// <summary>
+/// Defines a shared test collection so that all extractor test classes share a single
+/// <see cref="BaseExtractorTestClass"/> fixture instance. The fixture is created once
+/// before the first test runs and disposed once after the last test completes,
+/// avoiding the race condition where parallel class-level fixtures prematurely
+/// delete the shared temp directory while other classes are still running.
+/// </summary>
+[CollectionDefinition(Name)]
+public class ExtractorTestCollection : ICollectionFixture<BaseExtractorTestClass>
+{
+    public const string Name = "Extractor Tests";
+}

RecursiveExtractor.Tests/ExtractorTests/FilterTests.cs

@@ -7,7 +7,8 @@
 
 namespace RecursiveExtractor.Tests.ExtractorTests;
 
-public class FilterTests : IClassFixture<BaseExtractorTestClass>
+[Collection(ExtractorTestCollection.Name)]
+public class FilterTests
 {
     [Theory]
     [InlineData("TestData.zip")]

RecursiveExtractor.Tests/ExtractorTests/MiniMagicTests.cs

@@ -4,7 +4,8 @@
 
 namespace RecursiveExtractor.Tests.ExtractorTests;
 
-public class MiniMagicTests : IClassFixture<BaseExtractorTestClass>
+[Collection(ExtractorTestCollection.Name)]
+public class MiniMagicTests
 {
     [Theory]
     [InlineData("TestData.zip", ArchiveFileType.ZIP)]

RecursiveExtractor.Tests/ExtractorTests/TestQuinesAndSlip.cs

@@ -9,7 +9,8 @@
 
 namespace RecursiveExtractor.Tests.ExtractorTests;
 
-public class TestQuinesAndSlip : IClassFixture<BaseExtractorTestClass>
+[Collection(ExtractorTestCollection.Name)]
+public class TestQuinesAndSlip
 {
     public static IEnumerable<object[]> ZipSlipNames
     {

RecursiveExtractor.Tests/ExtractorTests/TimeOutTests.cs

@@ -6,7 +6,8 @@
 
 namespace RecursiveExtractor.Tests.ExtractorTests;
 
-public class TimeOutTests : IClassFixture<BaseExtractorTestClass>
+[Collection(ExtractorTestCollection.Name)]
+public class TimeOutTests
 {
     [Theory]
     [InlineData("TestData.7z", false)]