Fix VerifySettings copy constructor, temp cleanup, and stream/extensi…

docs/naming.md

@@ -789,7 +789,7 @@ public static string NameWithParent(this Type type)
     return type.Name;
 }
 ```
-<sup><a href='/src/Verify/Extensions.cs#L114-L126' title='Snippet source file'>snippet source</a> | <a href='#snippet-NameWithParent' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify/Extensions.cs#L123-L135' title='Snippet source file'>snippet source</a> | <a href='#snippet-NameWithParent' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 Any path calculated in `DerivePathInfo` should be fully qualified to remove the inconsistency of the current directory.

docs/temp-file.md

@@ -34,7 +34,7 @@ public void Usage()
     // file automatically deleted here
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L38-L50' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFile' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L87-L99' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFile' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -62,7 +62,7 @@ public void PathProperty()
     Assert.True(Path.IsPathRooted(path));
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L52-L62' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFilePathProperty' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L101-L111' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFilePathProperty' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -91,7 +91,7 @@ public void StringConversion()
     Trace.WriteLine(content);
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L344-L359' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileStringConversion' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L393-L408' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileStringConversion' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -114,7 +114,7 @@ public void FileInfoConversion()
     Trace.WriteLine(directoryName);
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L361-L375' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileFileInfoConversion' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L410-L424' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileFileInfoConversion' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -135,7 +135,7 @@ public void InfoProperty()
     Trace.WriteLine(directoryName);
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L377-L389' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileInfoProperty' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L426-L438' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileInfoProperty' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -151,7 +151,7 @@ public void RootDirectory() =>
     // Accessing the root directory for all TempDirectory instances
     Trace.WriteLine(TempFile.RootDirectory);
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L114-L121' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileRootDirectory' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L163-L170' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileRootDirectory' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -186,7 +186,7 @@ public async Task VerifyFileInstance()
     await VerifyFile(file);
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L26-L36' title='Snippet source file'>snippet source</a> | <a href='#snippet-VerifyTempFile' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L75-L85' title='Snippet source file'>snippet source</a> | <a href='#snippet-VerifyTempFile' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -207,7 +207,7 @@ public async Task Scrubbing()
     });
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L96-L110' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileScrubbing' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L145-L159' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileScrubbing' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 Result:
@@ -237,7 +237,7 @@ File.WriteAllText(temp, "content");
 
 // file automatically deleted here
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L620-L628' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreate' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L669-L677' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreate' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -252,7 +252,7 @@ using var temp = TempFile.Create(".txt");
 
 File.WriteAllText(temp, "content");
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L635-L641' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateWithExtension' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L684-L690' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateWithExtension' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -267,7 +267,7 @@ using var temp = TempFile.Create(".txt", Encoding.UTF8);
 
 File.Exists(temp.Path);
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L649-L655' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateWithEncoding' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L698-L704' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateWithEncoding' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -283,7 +283,7 @@ using var temp = await TempFile.CreateText("Hello, World!");
 var content = await File.ReadAllTextAsync(temp);
 Assert.Equal("Hello, World!", content);
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L661-L668' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateText' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L710-L717' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateText' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -304,7 +304,7 @@ using var temp = await TempFile.CreateText(json, ".json");
 var content = await File.ReadAllTextAsync(temp);
 Assert.Equal(json, content);
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L674-L688' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateTextWithExtension' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L723-L737' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateTextWithExtension' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -323,7 +323,7 @@ using var temp = await TempFile.CreateText(
 var content = await File.ReadAllTextAsync(temp, Encoding.UTF8);
 Assert.Equal("Content with special chars: äöü", content);
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L694-L704' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateTextWithEncoding' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L743-L753' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateTextWithEncoding' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -341,7 +341,7 @@ using var temp = await TempFile.CreateBinary(data);
 var readData = await File.ReadAllBytesAsync(temp);
 Assert.Equal(data, readData);
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L712-L721' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateBinary' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L761-L770' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateBinary' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -353,7 +353,7 @@ Assert.Equal(data, readData);
 byte[] data = [0x01, 0x02, 0x03, 0x04];
 using var temp = await TempFile.CreateBinary(data, ".bin");
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L727-L732' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateBinaryWithExtension' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L776-L781' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileCreateBinaryWithExtension' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 
@@ -384,7 +384,7 @@ public void NoUsing()
     Debug.WriteLine(temp);
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L79-L92' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileNoUsing' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L128-L141' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileNoUsing' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 The file can then be manually inspected.
@@ -408,7 +408,7 @@ public void OpenExplorerAndDebug()
     temp.OpenExplorerAndDebug();
 }
 ```
-<sup><a href='/src/Verify.Tests/TempFileTests.cs#L64-L77' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileOpenExplorerAndDebug' title='Start of snippet'>anchor</a></sup>
+<sup><a href='/src/Verify.Tests/TempFileTests.cs#L113-L126' title='Snippet source file'>snippet source</a> | <a href='#snippet-TempFileOpenExplorerAndDebug' title='Start of snippet'>anchor</a></sup>
 <!-- endSnippet -->
 
 This method is designed to help debug tests by enabling the inspection of the contents of the temporary file while the test is paused. It performs two actions:

src/Verify.Tests/CopyConstructorTests.cs

@@ -0,0 +1,58 @@
+public class CopyConstructorTests
+{
+    [Fact]
+    public void PreservesThrowException()
+    {
+        var settings = new VerifySettings();
+        settings.AutoVerify(throwException: true);
+
+        var copy = new VerifySettings(settings);
+
+        Assert.True(copy.throwException);
+    }
+
+    [Fact]
+    public void ClonesAppendedFiles()
+    {
+        var settings = new VerifySettings();
+        settings.AppendContentAsFile("base");
+
+        var copy = new VerifySettings(settings);
+        copy.AppendContentAsFile("extra");
+
+        // The base settings must not see the file appended to the copy.
+        Assert.Single(settings.appendedFiles!);
+        Assert.Equal(2, copy.appendedFiles!.Count);
+    }
+
+    [Fact]
+    public void ClonesExtensionStreamComparers()
+    {
+        var settings = new VerifySettings();
+        StreamCompare compare = (_, _, _) => Task.FromResult(CompareResult.Equal);
+        // Extensions unique to this test so the global comparer registry can't
+        // satisfy the lookup below.
+        settings.UseStreamComparer(compare, "copyctorext1");
+
+        var copy = new VerifySettings(settings);
+        copy.UseStreamComparer(compare, "copyctorext2");
+
+        // The comparer added to the copy must not leak into the base settings.
+        Assert.False(settings.TryFindStreamComparer("copyctorext2", out _));
+        Assert.True(copy.TryFindStreamComparer("copyctorext2", out _));
+    }
+
+    [Fact]
+    public void ClonesExtensionMappedScrubbers()
+    {
+        var settings = new VerifySettings();
+        settings.AddScrubber("txt", _ => { });
+
+        var copy = new VerifySettings(settings);
+        copy.AddScrubber("txt", _ => { });
+
+        // The inner list is shared unless deep-copied.
+        Assert.Single(settings.ExtensionMappedInstanceScrubbers!["txt"]);
+        Assert.Equal(2, copy.ExtensionMappedInstanceScrubbers!["txt"].Count);
+    }
+}

src/Verify.Tests/IoHelpersTests.cs

@@ -18,4 +18,44 @@ public void ResolveDirectoryNameFromSourceFileTests(string sourceFile, string ex
 
         Assert.Equal(expectedDirectory, IoHelpers.ResolveDirectoryFromSourceFile(sourceFile));
     }
+
+    [Fact]
+    public async Task WriteStreamHandlesExclusiveFileStream()
+    {
+        using var source = new TempFile(".bin");
+        await File.WriteAllBytesAsync(source, [1, 2, 3, 4, 5, 6, 7, 8]);
+        var destination = Path.Combine(Path.GetTempPath(), $"WriteStream{Guid.NewGuid():N}.bin");
+        try
+        {
+            // Writable + FileShare.None means File.Copy cannot re-open the source
+            // by path on Windows; WriteStream must fall back to the handle.
+            using var stream = new FileStream(source, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
+            await IoHelpers.WriteStream(destination, stream);
+
+            Assert.True(File.Exists(destination));
+            Assert.Equal(8, new FileInfo(destination).Length);
+        }
+        finally
+        {
+            File.Delete(destination);
+        }
+    }
+
+    [Fact]
+    public void ExtensionForExtensionlessFileStream()
+    {
+        var directory = Path.Combine(Path.GetTempPath(), $"ExtTest{Guid.NewGuid():N}");
+        Directory.CreateDirectory(directory);
+        var path = Path.Combine(directory, "Dockerfile");
+        File.WriteAllText(path, "content");
+        try
+        {
+            using var stream = File.OpenRead(path);
+            Assert.Equal("noextension", stream.Extension());
+        }
+        finally
+        {
+            Directory.Delete(directory, true);
+        }
+    }
 }

src/Verify.Tests/TempDirectoryTests.cs

@@ -427,6 +427,28 @@ public void IgnoreLockedFiles_DefaultIsFalse()
         }
     }
 
+    [Fact]
+    public void CleanupDoesNotThrowForUndeletableDirectory()
+    {
+        var directoryPath = Path.Combine(TempDirectory.RootDirectory, Path.GetRandomFileName());
+        Directory.CreateDirectory(directoryPath);
+        var filePath = Path.Combine(directoryPath, "locked.txt");
+        File.WriteAllText(filePath, "content");
+        PreventDeletion(filePath, directoryPath);
+        Directory.SetLastWriteTime(directoryPath, DateTime.Now.AddDays(-2));
+        try
+        {
+            // An aged-out orphan that cannot be deleted must not fail the whole
+            // module-initializer cleanup.
+            TempDirectory.Cleanup();
+        }
+        finally
+        {
+            AllowDeletion(filePath, directoryPath);
+            Directory.Delete(directoryPath, true);
+        }
+    }
+
     // On Windows, ReadOnly on a file prevents deletion.
     // On Unix, file deletion is controlled by the parent directory's write permission.
     static void PreventDeletion(string filePath, string directoryPath)

src/Verify.Tests/TempFileTests.cs

@@ -23,6 +23,55 @@ public void Constructor_WithExtension_AppliesExtension()
         Assert.EndsWith(".txt", temp.Path);
     }
 
+    [Fact]
+    public void CleanupDoesNotThrowForUndeletableFile()
+    {
+        var filePath = Path.Combine(TempFile.RootDirectory, $"undeletable{Guid.NewGuid():N}.txt");
+        File.WriteAllText(filePath, "content");
+        // Age the file out before marking it read-only: on .NET Framework the
+        // timestamp cannot be set on a read-only file.
+        File.SetLastWriteTime(filePath, DateTime.Now.AddDays(-2));
+        // On Windows a read-only file cannot be deleted; on Unix deletion is
+        // governed by the directory, so the file is deletable there and this
+        // test is a no-op guard.
+        var readOnly = RuntimeInformation.IsOSPlatform(OSPlatform.Windows);
+        if (readOnly)
+        {
+            File.SetAttributes(filePath, FileAttributes.ReadOnly);
+        }
+
+        try
+        {
+            TempFile.Cleanup();
+        }
+        finally
+        {
+            if (readOnly)
+            {
+                File.SetAttributes(filePath, FileAttributes.Normal);
+            }
+
+            if (File.Exists(filePath))
+            {
+                File.Delete(filePath);
+            }
+        }
+    }
+
+    [Fact]
+    public async Task ConcurrentInstancesDoNotCorruptState()
+    {
+        // Establish the shared async-local path list, then hammer it from many
+        // child contexts that flow the same list in.
+        using var parent = new TempFile();
+        var tasks = Enumerable.Range(0, 200)
+            .Select(_ => Task.Run(() =>
+            {
+                using var temp = new TempFile();
+            }));
+        await Task.WhenAll(tasks);
+    }
+
     #region VerifyTempFile
 
     [Fact]

src/Verify/Extensions.cs

@@ -20,8 +20,17 @@ static class Extensions
     public static bool IsNumeric(this Type type) =>
         numericTypes.Contains(Nullable.GetUnderlyingType(type) ?? type);
 
-    public static string Extension(this FileStream file) =>
-        Path.GetExtension(file.Name)[1..];
+    public static string Extension(this FileStream file)
+    {
+        var extension = Path.GetExtension(file.Name);
+        if (extension.Length == 0)
+        {
+            // Matches the convention used for extension-less directory entries.
+            return "noextension";
+        }
+
+        return extension[1..];
+    }
 
     public static Version MajorMinor(this Version version) =>
         new(version.Major, version.Minor);