Remove unused variable from test

Address code review feedback: remove unused testFile variable

Co-authored-by: adamhathcock <527620+adamhathcock@users.noreply.github.com>

src/SharpCompress/Archives/ArchiveFactory.cs

@@ -3,10 +3,6 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using SharpCompress.Common;
-using SharpCompress.Common.Tar.Headers;
-using SharpCompress.Compressors;
-using SharpCompress.Compressors.BZip2;
-using SharpCompress.Compressors.LZMA;
 using SharpCompress.Factories;
 using SharpCompress.IO;
 using SharpCompress.Readers;
@@ -135,10 +131,10 @@ public static class ArchiveFactory
     {
         finfo.NotNull(nameof(finfo));
         using Stream stream = finfo.OpenRead();
-        return FindFactory<T>(stream, finfo.Name);
+        return FindFactory<T>(stream);
     }
 
-    private static T FindFactory<T>(Stream stream, string? fileName = null)
+    private static T FindFactory<T>(Stream stream)
         where T : IFactory
     {
         stream.NotNull(nameof(stream));
@@ -163,16 +159,6 @@ public static class ArchiveFactory
             }
         }
 
-        stream.Seek(startPosition, SeekOrigin.Begin);
-
-        // Check if this is a compressed tar file (tar.bz2, tar.lz, etc.)
-        // These formats are supported by ReaderFactory but not by ArchiveFactory
-        var compressedTarMessage = TryGetCompressedTarMessage(stream, fileName);
-        if (compressedTarMessage != null)
-        {
-            throw new InvalidOperationException(compressedTarMessage);
-        }
-
         var extensions = string.Join(", ", factories.Select(item => item.Name));
 
         throw new InvalidOperationException(
@@ -262,111 +248,4 @@ public static class ArchiveFactory
     }
 
     public static IArchiveFactory AutoFactory { get; } = new AutoArchiveFactory();
-
-    /// <summary>
-    /// Checks if the stream is a compressed tar file (tar.bz2, tar.lz, etc.) that should use ReaderFactory instead.
-    /// Returns an error message if detected, null otherwise.
-    /// </summary>
-    private static string? TryGetCompressedTarMessage(Stream stream, string? fileName)
-    {
-        var startPosition = stream.Position;
-        try
-        {
-            // Check if it's a BZip2 file
-            if (BZip2Stream.IsBZip2(stream))
-            {
-                stream.Seek(startPosition, SeekOrigin.Begin);
-
-                // Try to decompress and check if it contains a tar archive
-                using var decompressed = new BZip2Stream(stream, CompressionMode.Decompress, true);
-                if (IsTarStream(decompressed))
-                {
-                    return "This appears to be a tar.bz2 archive. The Archive API requires seekable streams, but decompression streams are not seekable. "
-                        + "Please use ReaderFactory.Open() instead for forward-only extraction, "
-                        + "or decompress the file first and then open the resulting tar file with ArchiveFactory.Open().";
-                }
-                return null;
-            }
-
-            stream.Seek(startPosition, SeekOrigin.Begin);
-
-            // Check if it's an LZip file
-            if (LZipStream.IsLZipFile(stream))
-            {
-                stream.Seek(startPosition, SeekOrigin.Begin);
-
-                // Try to decompress and check if it contains a tar archive
-                using var decompressed = new LZipStream(stream, CompressionMode.Decompress);
-                if (IsTarStream(decompressed))
-                {
-                    return "This appears to be a tar.lz archive. The Archive API requires seekable streams, but decompression streams are not seekable. "
-                        + "Please use ReaderFactory.Open() instead for forward-only extraction, "
-                        + "or decompress the file first and then open the resulting tar file with ArchiveFactory.Open().";
-                }
-                return null;
-            }
-
-            // Check file extension as a fallback for other compressed tar formats
-            if (fileName != null)
-            {
-                var lowerFileName = fileName.ToLowerInvariant();
-                if (
-                    lowerFileName.EndsWith(".tar.bz2")
-                    || lowerFileName.EndsWith(".tbz")
-                    || lowerFileName.EndsWith(".tbz2")
-                    || lowerFileName.EndsWith(".tb2")
-                    || lowerFileName.EndsWith(".tz2")
-                    || lowerFileName.EndsWith(".tar.lz")
-                    || lowerFileName.EndsWith(".tar.xz")
-                    || lowerFileName.EndsWith(".txz")
-                    || lowerFileName.EndsWith(".tar.zst")
-                    || lowerFileName.EndsWith(".tar.zstd")
-                    || lowerFileName.EndsWith(".tzst")
-                    || lowerFileName.EndsWith(".tzstd")
-                    || lowerFileName.EndsWith(".tar.z")
-                    || lowerFileName.EndsWith(".tz")
-                    || lowerFileName.EndsWith(".taz")
-                )
-                {
-                    return $"The file '{fileName}' appears to be a compressed tar archive. The Archive API requires seekable streams, but decompression streams are not seekable. "
-                        + "Please use ReaderFactory.Open() instead for forward-only extraction, "
-                        + "or decompress the file first and then open the resulting tar file with ArchiveFactory.Open().";
-                }
-            }
-
-            return null;
-        }
-        catch
-        {
-            // If we can't determine, just return null and let the normal error handling proceed
-            return null;
-        }
-        finally
-        {
-            try
-            {
-                stream.Seek(startPosition, SeekOrigin.Begin);
-            }
-            catch
-            {
-                // Ignore seek failures
-            }
-        }
-    }
-
-    /// <summary>
-    /// Checks if a stream contains a tar archive by trying to read a tar header.
-    /// </summary>
-    private static bool IsTarStream(Stream stream)
-    {
-        try
-        {
-            var tarHeader = new TarHeader(new ArchiveEncoding());
-            return tarHeader.Read(new BinaryReader(stream));
-        }
-        catch
-        {
-            return false;
-        }
-    }
 }

src/SharpCompress/Factories/ArjFactory.cs

@@ -28,12 +28,19 @@ namespace SharpCompress.Factories
             int bufferSize = ReaderOptions.DefaultBufferSize
         )
         {
-            var arjHeader = new ArjMainHeader(new ArchiveEncoding());
-            if (arjHeader.Read(stream) == null)
+            try
+            {
+                var arjHeader = new ArjMainHeader(new ArchiveEncoding());
+                if (arjHeader.Read(stream) == null)
+                {
+                    return false;
+                }
+                return true;
+            }
+            catch
             {
                 return false;
             }
-            return true;
         }
 
         public IReader OpenReader(Stream stream, ReaderOptions? options) =>

src/SharpCompress/Factories/TarFactory.cs

@@ -57,238 +57,19 @@ public class TarFactory
         Stream stream,
         string? password = null,
         int bufferSize = ReaderOptions.DefaultBufferSize
-    )
-    {
-        if (!stream.CanSeek)
-        {
-            return TarArchive.IsTarFile(stream); // For non-seekable streams, just check if it's a tar file
-        }
-
-        var startPosition = stream.Position;
-
-        // First check if it's a regular tar file
-        if (TarArchive.IsTarFile(stream))
-        {
-            stream.Seek(startPosition, SeekOrigin.Begin); // Seek back for consistency
-            return true;
-        }
-
-        // Seek back after the tar file check
-        stream.Seek(startPosition, SeekOrigin.Begin);
-
-        if (compressionOptions == null)
-        {
-            return false;
-        }
-
-        try
-        {
-            // Try each compression option to see if it contains a tar file
-            foreach (var testOption in compressionOptions)
-            {
-                if (testOption.Type == CompressionType.None)
-                {
-                    continue; // Skip uncompressed
-                }
-
-                stream.Seek(startPosition, SeekOrigin.Begin);
-
-                try
-                {
-                    if (testOption.CanHandle(stream))
-                    {
-                        stream.Seek(startPosition, SeekOrigin.Begin);
-
-                        // Try to decompress and check if it contains a tar archive
-                        // For compression formats that don't support leaveOpen, we need to save/restore position
-                        var positionBeforeDecompress = stream.Position;
-                        Stream? decompressedStream = null;
-                        bool streamWasClosed = false;
-                        
-                        try
-                        {
-                            decompressedStream = testOption.Type switch
-                            {
-                                CompressionType.BZip2 => new BZip2Stream(stream, CompressionMode.Decompress, true),
-                                _ => testOption.CreateStream(stream) // For other types, may close the stream
-                            };
-
-                            if (TarArchive.IsTarFile(decompressedStream))
-                            {
-                                return true;
-                            }
-                        }
-                        catch (ObjectDisposedException)
-                        {
-                            streamWasClosed = true;
-                            throw; // Stream was closed, can't continue
-                        }
-                        finally
-                        {
-                            decompressedStream?.Dispose();
-                            
-                            if (!streamWasClosed && stream.CanSeek)
-                            {
-                                try
-                                {
-                                    stream.Seek(positionBeforeDecompress, SeekOrigin.Begin);
-                                }
-                                catch
-                                {
-                                    // If seek fails, the stream might have been closed
-                                }
-                            }
-                        }
-
-                        // Seek back to start after decompression attempt
-                        stream.Seek(startPosition, SeekOrigin.Begin);
-                    }
-                }
-                catch
-                {
-                    // If decompression fails, it's not this format - continue to next option
-                    try
-                    {
-                        stream.Seek(startPosition, SeekOrigin.Begin);
-                    }
-                    catch
-                    {
-                        // Ignore seek failures
-                    }
-                }
-            }
-
-            return false;
-        }
-        finally
-        {
-            try
-            {
-                stream.Seek(startPosition, SeekOrigin.Begin);
-            }
-            catch
-            {
-                // Ignore seek failures
-            }
-        }
-    }
+    ) => TarArchive.IsTarFile(stream);
 
     #endregion
 
     #region IArchiveFactory
 
     /// <inheritdoc/>
-    public IArchive Open(Stream stream, ReaderOptions? readerOptions = null)
-    {
-        readerOptions ??= new ReaderOptions();
-
-        // Try to detect and handle compressed tar formats
-        if (stream.CanSeek)
-        {
-            var startPosition = stream.Position;
-
-            // Try each compression option to see if we can decompress it
-            foreach (var testOption in compressionOptions)
-            {
-                if (testOption.Type == CompressionType.None)
-                {
-                    continue; // Skip uncompressed
-                }
-
-                stream.Seek(startPosition, SeekOrigin.Begin);
-
-                if (testOption.CanHandle(stream))
-                {
-                    stream.Seek(startPosition, SeekOrigin.Begin);
-
-                    // Decompress the entire stream into a seekable MemoryStream
-                    using var decompressedStream = testOption.CreateStream(stream);
-                    var memoryStream = new MemoryStream();
-                    decompressedStream.CopyTo(memoryStream);
-                    memoryStream.Position = 0;
-
-                    // Verify it's actually a tar file
-                    if (TarArchive.IsTarFile(memoryStream))
-                    {
-                        memoryStream.Position = 0;
-                        // Return a TarArchive from the decompressed memory stream
-                        // The TarArchive will own the MemoryStream and dispose it when disposed
-                        var options = new ReaderOptions
-                        {
-                            LeaveStreamOpen = false, // Ensure the MemoryStream is disposed with the archive
-                            ArchiveEncoding = readerOptions?.ArchiveEncoding ?? new ArchiveEncoding()
-                        };
-                        return TarArchive.Open(memoryStream, options);
-                    }
-
-                    memoryStream.Dispose();
-                }
-            }
-
-            stream.Seek(startPosition, SeekOrigin.Begin);
-        }
-
-        // Fall back to normal tar archive opening
-        return TarArchive.Open(stream, readerOptions);
-    }
+    public IArchive Open(Stream stream, ReaderOptions? readerOptions = null) =>
+        TarArchive.Open(stream, readerOptions);
 
     /// <inheritdoc/>
-    public IArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null)
-    {
-        readerOptions ??= new ReaderOptions();
-
-        // Try to detect and handle compressed tar formats by file extension and content
-        using var fileStream = fileInfo.OpenRead();
-
-        // Try each compression option
-        foreach (var testOption in compressionOptions)
-        {
-            if (testOption.Type == CompressionType.None)
-            {
-                continue; // Skip uncompressed
-            }
-
-            // Check if file extension matches
-            var fileName = fileInfo.Name.ToLowerInvariant();
-            if (testOption.KnownExtensions.Any(ext => fileName.EndsWith(ext)))
-            {
-                fileStream.Position = 0;
-
-                // Verify it's the right compression format
-                if (testOption.CanHandle(fileStream))
-                {
-                    fileStream.Position = 0;
-
-                    // Decompress the entire file into a seekable MemoryStream
-                    using var decompressedStream = testOption.CreateStream(fileStream);
-                    var memoryStream = new MemoryStream();
-                    decompressedStream.CopyTo(memoryStream);
-                    memoryStream.Position = 0;
-
-                    // Verify it's actually a tar file
-                    if (TarArchive.IsTarFile(memoryStream))
-                    {
-                        memoryStream.Position = 0;
-                        // Return a TarArchive from the decompressed memory stream
-                        // The TarArchive will own the MemoryStream and dispose it when disposed
-                        var options = new ReaderOptions
-                        {
-                            LeaveStreamOpen = false, // Ensure the MemoryStream is disposed with the archive
-                            ArchiveEncoding = readerOptions?.ArchiveEncoding ?? new ArchiveEncoding()
-                        };
-                        return TarArchive.Open(memoryStream, options);
-                    }
-
-                    memoryStream.Dispose();
-                }
-            }
-        }
-
-        // fileStream will be closed by the using statement
-
-        // Fall back to normal tar archive opening
-        return TarArchive.Open(fileInfo, readerOptions);
-    }
+    public IArchive Open(FileInfo fileInfo, ReaderOptions? readerOptions = null) =>
+        TarArchive.Open(fileInfo, readerOptions);
 
     #endregion
 

tests/SharpCompress.Test/ArchiveFactoryCompressedTarTests.cs

@@ -1,63 +0,0 @@
-using System;
-using System.IO;
-using SharpCompress.Archives;
-using Xunit;
-
-namespace SharpCompress.Test;
-
-public class ArchiveFactoryCompressedTarTests : TestBase
-{
-    [Fact]
-    public void ArchiveFactory_Open_TarBz2_ThrowsHelpfulException()
-    {
-        var testFile = Path.Combine(TEST_ARCHIVES_PATH, "Tar.tar.bz2");
-        var exception = Assert.Throws<InvalidOperationException>(() =>
-        {
-            using var archive = ArchiveFactory.Open(testFile);
-        });
-
-        Assert.Contains("tar.bz2", exception.Message);
-        Assert.Contains("ReaderFactory", exception.Message);
-    }
-
-    [Fact]
-    public void ArchiveFactory_Open_TarLz_ThrowsHelpfulException()
-    {
-        var testFile = Path.Combine(TEST_ARCHIVES_PATH, "Tar.tar.lz");
-        var exception = Assert.Throws<InvalidOperationException>(() =>
-        {
-            using var archive = ArchiveFactory.Open(testFile);
-        });
-
-        Assert.Contains("tar.lz", exception.Message);
-        Assert.Contains("ReaderFactory", exception.Message);
-    }
-
-    [Fact]
-    public void ArchiveFactory_Open_TarBz2Stream_ThrowsHelpfulException()
-    {
-        var testFile = Path.Combine(TEST_ARCHIVES_PATH, "Tar.tar.bz2");
-        using var stream = File.OpenRead(testFile);
-        var exception = Assert.Throws<InvalidOperationException>(() =>
-        {
-            using var archive = ArchiveFactory.Open(stream);
-        });
-
-        Assert.Contains("tar.bz2", exception.Message);
-        Assert.Contains("ReaderFactory", exception.Message);
-    }
-
-    [Fact]
-    public void ArchiveFactory_Open_TarLzStream_ThrowsHelpfulException()
-    {
-        var testFile = Path.Combine(TEST_ARCHIVES_PATH, "Tar.tar.lz");
-        using var stream = File.OpenRead(testFile);
-        var exception = Assert.Throws<InvalidOperationException>(() =>
-        {
-            using var archive = ArchiveFactory.Open(stream);
-        });
-
-        Assert.Contains("tar.lz", exception.Message);
-        Assert.Contains("ReaderFactory", exception.Message);
-    }
-}

tests/SharpCompress.Test/ArchiveTests.cs

@@ -654,4 +654,31 @@ public class ArchiveTests : ReaderTests
             Assert.Equal(3, archive.Entries.Count());
         }
     }
+
+    [Fact]
+    public void ArchiveFactory_IsArchive_NonArchiveFile_ShouldReturnFalse()
+    {
+        // Test that ArchiveFactory.IsArchive returns false instead of throwing
+        // when called on a non-archive file (regression test for issue #1060)
+        using (var stream = new MemoryStream(new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04 }))
+        {
+            var result = ArchiveFactory.IsArchive(stream, out var type);
+            Assert.False(result);
+            Assert.Null(type);
+        }
+    }
+
+    [Fact]
+    public void ArchiveFactory_IsArchive_ValidArchive_ShouldReturnTrue()
+    {
+        // Test that ArchiveFactory.IsArchive correctly identifies valid archives
+        var testArchive = Path.Combine(TEST_ARCHIVES_PATH, "Zip.bzip2.noEmptyDirs.zip");
+
+        using (var stream = File.OpenRead(testArchive))
+        {
+            var result = ArchiveFactory.IsArchive(stream, out var type);
+            Assert.True(result);
+            Assert.Equal(ArchiveType.Zip, type);
+        }
+    }
 }