fix: file stream sharing

src/TestableIO.System.IO.Abstractions.TestingHelpers/FileHandles.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Collections.Concurrent;
+using System.IO;
+using System.IO.Abstractions.TestingHelpers;
+
+public class FileHandles
+{
+    private readonly ConcurrentDictionary<string, ConcurrentDictionary<Guid, (FileAccess access, FileShare share)>> handles = new();
+
+    public void TryAddHandle(string path, Guid guid, FileAccess access, FileShare share)
+    {
+        var pathHandles = handles.GetOrAdd(
+            path, 
+            _ => new ConcurrentDictionary<Guid, (FileAccess, FileShare)>());
+
+        var requiredShare = AccessToShare(access);
+        foreach (var (existingAccess, existingShare) in pathHandles.Values)
+        {
+            var existingRequiredShare = AccessToShare(existingAccess);
+            var existingBlocksNew = (existingShare & requiredShare) != requiredShare;
+            var newBlocksExisting = (share & existingRequiredShare) != existingRequiredShare;
+            if (existingBlocksNew || newBlocksExisting)
+            {
+                throw CommonExceptions.ProcessCannotAccessFileInUse(path);
+            }
+        }
+
+        pathHandles[guid] = (access, share);
+    }
+
+    public void RemoveHandle(string path, Guid guid)
+    {
+        if (handles.TryGetValue(path, out var pathHandles))
+        {
+            pathHandles.TryRemove(guid, out _);
+            if (pathHandles.IsEmpty)
+            {
+                handles.TryRemove(path, out _);
+            }
+        }
+    }
+
+    private static FileShare AccessToShare(FileAccess access)
+    {
+        var share = FileShare.None;
+        if (access.HasFlag(FileAccess.Read))
+        {
+            share |= FileShare.Read;
+        }
+        if (access.HasFlag(FileAccess.Write))
+        {
+            share |= FileShare.Write;
+        }
+        return share;
+    }
+}

src/TestableIO.System.IO.Abstractions.TestingHelpers/IMockFileDataAccessor.cs

@@ -1,5 +1,4 @@
-using System.Collections.Concurrent;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Reflection;
 
 namespace System.IO.Abstractions.TestingHelpers;
@@ -115,5 +114,5 @@ public interface IMockFileDataAccessor : IFileSystem
     /// <summary>
     /// Gets a reference to the open file handles.
     /// </summary>
-    ConcurrentDictionary<string, ConcurrentDictionary<Guid, (FileAccess, FileShare)>> FileHandles { get; }
+    FileHandles FileHandles { get; }
 }

src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileStream.cs

@@ -2,7 +2,6 @@
 using System.Threading;
 using System.Runtime.Versioning;
 using System.Security.AccessControl;
-using System.Collections.Concurrent;
 
 namespace System.IO.Abstractions.TestingHelpers;
 
@@ -102,41 +101,11 @@ public MockFileStream(
             mockFileDataAccessor.AddFile(path, fileData);
         }
 
-        var fileHandlesEntry = mockFileDataAccessor.FileHandles.GetOrAdd(
-            path, 
-            _ => new ConcurrentDictionary<Guid, (FileAccess access, FileShare share)>());
-
-        var requiredShare = AccessToShare(access);
-        foreach (var (existingAccess, existingShare) in fileHandlesEntry.Values)
-        {
-            var existingRequiredShare = AccessToShare(existingAccess);
-            var existingBlocksNew = (existingShare & requiredShare) != requiredShare;
-            var newBlocksExisting = (share & existingRequiredShare) != existingRequiredShare;
-            if (existingBlocksNew || newBlocksExisting)
-            {
-                throw CommonExceptions.ProcessCannotAccessFileInUse(path);
-            }
-        }
-
-        fileHandlesEntry[guid] = (access, share);
+        mockFileDataAccessor.FileHandles.TryAddHandle(path, guid, access, share);
         this.access = access;
         this.share = share;
     }
 
-    private static FileShare AccessToShare(FileAccess access)
-    {
-        var share = FileShare.None;
-        if (access.HasFlag(FileAccess.Read))
-        {
-            share |= FileShare.Read;
-        }
-        if (access.HasFlag(FileAccess.Write))
-        {
-            share |= FileShare.Write;
-        }
-        return share;
-    }
-
     private static void ThrowIfInvalidModeAccess(FileMode mode, FileAccess access)
     {
         if (mode == FileMode.Append)
@@ -181,14 +150,7 @@ protected override void Dispose(bool disposing)
         {
             return;
         }
-        if (mockFileDataAccessor.FileHandles.TryGetValue(path, out var fileHandlesEntry))
-        {
-            fileHandlesEntry.TryRemove(guid, out _);
-            if (fileHandlesEntry.IsEmpty)
-            {
-                mockFileDataAccessor.FileHandles.TryRemove(path, out _);
-            }
-        }
+        mockFileDataAccessor.FileHandles.RemoveHandle(path, guid);
         InternalFlush();
         base.Dispose(disposing);
         OnClose();

src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileSystem.cs

@@ -1,4 +1,3 @@
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
@@ -23,7 +22,7 @@ public class MockFileSystem : FileSystemBase, IMockFileDataAccessor
 #if FEATURE_SERIALIZABLE
     [NonSerialized]
 #endif
-    private readonly ConcurrentDictionary<string, ConcurrentDictionary<Guid, (FileAccess access, FileShare share)>> fileHandles = new();
+    private readonly FileHandles fileHandles = new();
 #if FEATURE_SERIALIZABLE
     [NonSerialized]
 #endif
@@ -120,8 +119,7 @@ public MockFileSystem(IDictionary<string, MockFileData> files, MockFileSystemOpt
     /// <inheritdoc />
     public PathVerifier PathVerifier => pathVerifier;
     /// <inheritdoc />
-    public ConcurrentDictionary<string, ConcurrentDictionary<Guid, (FileAccess, FileShare)>> FileHandles
-    => fileHandles;
+    public FileHandles FileHandles => fileHandles;
 
     /// <summary>
     /// Replaces the time provider with a mocked instance. This allows to influence the used time in tests.

tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net10.0.txt

@@ -1,5 +1,11 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/TestableIO/System.IO.Abstractions.git")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v10.0", FrameworkDisplayName=".NET 10.0")]
+public class FileHandles
+{
+    public FileHandles() { }
+    public void RemoveHandle(string path, System.Guid guid) { }
+    public void TryAddHandle(string path, System.Guid guid, System.IO.FileAccess access, System.IO.FileShare share) { }
+}
 namespace System.IO.Abstractions.TestingHelpers
 {
     public interface IMockFileDataAccessor : System.IO.Abstractions.IFileSystem
@@ -8,7 +14,7 @@ namespace System.IO.Abstractions.TestingHelpers
         System.Collections.Generic.IEnumerable<string> AllDrives { get; }
         System.Collections.Generic.IEnumerable<string> AllFiles { get; }
         System.Collections.Generic.IEnumerable<string> AllPaths { get; }
-        System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        FileHandles FileHandles { get; }
         System.IO.Abstractions.IFileSystem FileSystem { get; }
         System.IO.Abstractions.TestingHelpers.PathVerifier PathVerifier { get; }
         System.IO.Abstractions.TestingHelpers.StringOperations StringOperations { get; }
@@ -441,7 +447,7 @@ namespace System.IO.Abstractions.TestingHelpers
         public override System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public override System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
         public override System.IO.Abstractions.IFile File { get; }
-        public System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        public FileHandles FileHandles { get; }
         public override System.IO.Abstractions.IFileInfoFactory FileInfo { get; }
         public override System.IO.Abstractions.IFileStreamFactory FileStream { get; }
         public System.IO.Abstractions.IFileSystem FileSystem { get; }

tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net472.txt

@@ -1,5 +1,11 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/TestableIO/System.IO.Abstractions.git")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETFramework,Version=v4.7.2", FrameworkDisplayName=".NET Framework 4.7.2")]
+public class FileHandles
+{
+    public FileHandles() { }
+    public void RemoveHandle(string path, System.Guid guid) { }
+    public void TryAddHandle(string path, System.Guid guid, System.IO.FileAccess access, System.IO.FileShare share) { }
+}
 namespace System.IO.Abstractions.TestingHelpers
 {
     public interface IMockFileDataAccessor : System.IO.Abstractions.IFileSystem
@@ -8,7 +14,7 @@ namespace System.IO.Abstractions.TestingHelpers
         System.Collections.Generic.IEnumerable<string> AllDrives { get; }
         System.Collections.Generic.IEnumerable<string> AllFiles { get; }
         System.Collections.Generic.IEnumerable<string> AllPaths { get; }
-        System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        FileHandles FileHandles { get; }
         System.IO.Abstractions.IFileSystem FileSystem { get; }
         System.IO.Abstractions.TestingHelpers.PathVerifier PathVerifier { get; }
         System.IO.Abstractions.TestingHelpers.StringOperations StringOperations { get; }
@@ -348,7 +354,7 @@ namespace System.IO.Abstractions.TestingHelpers
         public override System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public override System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
         public override System.IO.Abstractions.IFile File { get; }
-        public System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        public FileHandles FileHandles { get; }
         public override System.IO.Abstractions.IFileInfoFactory FileInfo { get; }
         public override System.IO.Abstractions.IFileStreamFactory FileStream { get; }
         public System.IO.Abstractions.IFileSystem FileSystem { get; }

tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net6.0.txt

@@ -1,5 +1,11 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/TestableIO/System.IO.Abstractions.git")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v6.0", FrameworkDisplayName=".NET 6.0")]
+public class FileHandles
+{
+    public FileHandles() { }
+    public void RemoveHandle(string path, System.Guid guid) { }
+    public void TryAddHandle(string path, System.Guid guid, System.IO.FileAccess access, System.IO.FileShare share) { }
+}
 namespace System.IO.Abstractions.TestingHelpers
 {
     public interface IMockFileDataAccessor : System.IO.Abstractions.IFileSystem
@@ -8,7 +14,7 @@ namespace System.IO.Abstractions.TestingHelpers
         System.Collections.Generic.IEnumerable<string> AllDrives { get; }
         System.Collections.Generic.IEnumerable<string> AllFiles { get; }
         System.Collections.Generic.IEnumerable<string> AllPaths { get; }
-        System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        FileHandles FileHandles { get; }
         System.IO.Abstractions.IFileSystem FileSystem { get; }
         System.IO.Abstractions.TestingHelpers.PathVerifier PathVerifier { get; }
         System.IO.Abstractions.TestingHelpers.StringOperations StringOperations { get; }
@@ -403,7 +409,7 @@ namespace System.IO.Abstractions.TestingHelpers
         public override System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public override System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
         public override System.IO.Abstractions.IFile File { get; }
-        public System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        public FileHandles FileHandles { get; }
         public override System.IO.Abstractions.IFileInfoFactory FileInfo { get; }
         public override System.IO.Abstractions.IFileStreamFactory FileStream { get; }
         public System.IO.Abstractions.IFileSystem FileSystem { get; }

tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net8.0.txt

@@ -1,5 +1,11 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/TestableIO/System.IO.Abstractions.git")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v8.0", FrameworkDisplayName=".NET 8.0")]
+public class FileHandles
+{
+    public FileHandles() { }
+    public void RemoveHandle(string path, System.Guid guid) { }
+    public void TryAddHandle(string path, System.Guid guid, System.IO.FileAccess access, System.IO.FileShare share) { }
+}
 namespace System.IO.Abstractions.TestingHelpers
 {
     public interface IMockFileDataAccessor : System.IO.Abstractions.IFileSystem
@@ -8,7 +14,7 @@ namespace System.IO.Abstractions.TestingHelpers
         System.Collections.Generic.IEnumerable<string> AllDrives { get; }
         System.Collections.Generic.IEnumerable<string> AllFiles { get; }
         System.Collections.Generic.IEnumerable<string> AllPaths { get; }
-        System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        FileHandles FileHandles { get; }
         System.IO.Abstractions.IFileSystem FileSystem { get; }
         System.IO.Abstractions.TestingHelpers.PathVerifier PathVerifier { get; }
         System.IO.Abstractions.TestingHelpers.StringOperations StringOperations { get; }
@@ -427,7 +433,7 @@ namespace System.IO.Abstractions.TestingHelpers
         public override System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public override System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
         public override System.IO.Abstractions.IFile File { get; }
-        public System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        public FileHandles FileHandles { get; }
         public override System.IO.Abstractions.IFileInfoFactory FileInfo { get; }
         public override System.IO.Abstractions.IFileStreamFactory FileStream { get; }
         public System.IO.Abstractions.IFileSystem FileSystem { get; }

tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_net9.0.txt

@@ -1,5 +1,11 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/TestableIO/System.IO.Abstractions.git")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETCoreApp,Version=v9.0", FrameworkDisplayName=".NET 9.0")]
+public class FileHandles
+{
+    public FileHandles() { }
+    public void RemoveHandle(string path, System.Guid guid) { }
+    public void TryAddHandle(string path, System.Guid guid, System.IO.FileAccess access, System.IO.FileShare share) { }
+}
 namespace System.IO.Abstractions.TestingHelpers
 {
     public interface IMockFileDataAccessor : System.IO.Abstractions.IFileSystem
@@ -8,7 +14,7 @@ namespace System.IO.Abstractions.TestingHelpers
         System.Collections.Generic.IEnumerable<string> AllDrives { get; }
         System.Collections.Generic.IEnumerable<string> AllFiles { get; }
         System.Collections.Generic.IEnumerable<string> AllPaths { get; }
-        System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        FileHandles FileHandles { get; }
         System.IO.Abstractions.IFileSystem FileSystem { get; }
         System.IO.Abstractions.TestingHelpers.PathVerifier PathVerifier { get; }
         System.IO.Abstractions.TestingHelpers.StringOperations StringOperations { get; }
@@ -441,7 +447,7 @@ namespace System.IO.Abstractions.TestingHelpers
         public override System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public override System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
         public override System.IO.Abstractions.IFile File { get; }
-        public System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        public FileHandles FileHandles { get; }
         public override System.IO.Abstractions.IFileInfoFactory FileInfo { get; }
         public override System.IO.Abstractions.IFileStreamFactory FileStream { get; }
         public System.IO.Abstractions.IFileSystem FileSystem { get; }

tests/TestableIO.System.IO.Abstractions.Api.Tests/Expected/TestableIO.System.IO.Abstractions.TestingHelpers_netstandard2.0.txt

@@ -1,5 +1,11 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/TestableIO/System.IO.Abstractions.git")]
 [assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.0", FrameworkDisplayName=".NET Standard 2.0")]
+public class FileHandles
+{
+    public FileHandles() { }
+    public void RemoveHandle(string path, System.Guid guid) { }
+    public void TryAddHandle(string path, System.Guid guid, System.IO.FileAccess access, System.IO.FileShare share) { }
+}
 namespace System.IO.Abstractions.TestingHelpers
 {
     public interface IMockFileDataAccessor : System.IO.Abstractions.IFileSystem
@@ -8,7 +14,7 @@ namespace System.IO.Abstractions.TestingHelpers
         System.Collections.Generic.IEnumerable<string> AllDrives { get; }
         System.Collections.Generic.IEnumerable<string> AllFiles { get; }
         System.Collections.Generic.IEnumerable<string> AllPaths { get; }
-        System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        FileHandles FileHandles { get; }
         System.IO.Abstractions.IFileSystem FileSystem { get; }
         System.IO.Abstractions.TestingHelpers.PathVerifier PathVerifier { get; }
         System.IO.Abstractions.TestingHelpers.StringOperations StringOperations { get; }
@@ -348,7 +354,7 @@ namespace System.IO.Abstractions.TestingHelpers
         public override System.IO.Abstractions.IDirectoryInfoFactory DirectoryInfo { get; }
         public override System.IO.Abstractions.IDriveInfoFactory DriveInfo { get; }
         public override System.IO.Abstractions.IFile File { get; }
-        public System.Collections.Concurrent.ConcurrentDictionary<string, System.Collections.Concurrent.ConcurrentDictionary<System.Guid, System.ValueTuple<System.IO.FileAccess, System.IO.FileShare>>> FileHandles { get; }
+        public FileHandles FileHandles { get; }
         public override System.IO.Abstractions.IFileInfoFactory FileInfo { get; }
         public override System.IO.Abstractions.IFileStreamFactory FileStream { get; }
         public System.IO.Abstractions.IFileSystem FileSystem { get; }