Add TarEntryFormat parameter to TarFile.CreateFromDirectory methods

[iremyux]

This PR adds new overloads to TarFile.CreateFromDirectory and TarFile.CreateFromDirectoryAsync that accept a TarEntryFormat parameter, allowing users to specify the tar archive format when creating archives from directories. Currently, TarFile.CreateFromDirectory always creates archives using TarEntryFormat.Pax.

API Changes

namespace System.Formats.Tar;

public static partial class TarFile
{
    // New overloads:
    public static void CreateFromDirectory(string sourceDirectoryName, Stream destination, bool includeBaseDirectory, TarEntryFormat format);
    public static void CreateFromDirectory(string sourceDirectoryName, string destinationFileName, bool includeBaseDirectory, TarEntryFormat format);
    public static Task CreateFromDirectoryAsync(string sourceDirectoryName, Stream destination, bool includeBaseDirectory, TarEntryFormat format, CancellationToken cancellationToken = default);
    public static Task CreateFromDirectoryAsync(string sourceDirectoryName, string destinationFileName, bool includeBaseDirectory, TarEntryFormat format, CancellationToken cancellationToken = default);
}

Implements #121819

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[Copilot]

Pull request overview

This PR adds new overloads to TarFile.CreateFromDirectory and TarFile.CreateFromDirectoryAsync methods that accept a TarEntryFormat parameter, allowing users to specify the tar archive format (V7, Ustar, Pax, or Gnu) when creating archives from directories. Previously, these methods always used the Pax format by default.

Changes:

• Added four new public API overloads with TarEntryFormat parameter
• Modified existing overloads to delegate to new overloads with TarEntryFormat.Pax as default
• Added ValidateTarEntryFormat helper method to validate format parameter
• Added comprehensive test coverage for the new overloads

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/libraries/System.Formats.Tar/ref/System.Formats.Tar.cs	Added four new public API signatures for CreateFromDirectory and CreateFromDirectoryAsync with TarEntryFormat parameter
src/libraries/System.Formats.Tar/src/System/Formats/Tar/TarFile.cs	Implemented new overloads, added format validation, updated internal methods to accept format parameter, modified existing methods to delegate with Pax default
src/libraries/System.Formats.Tar/tests/TarFile/TarFile.CreateFromDirectory.Stream.Tests.cs	Added tests for invalid format validation and format-specific archive creation
src/libraries/System.Formats.Tar/tests/TarFile/TarFile.CreateFromDirectory.File.Tests.cs	Added tests for invalid format validation and format-specific archive creation
src/libraries/System.Formats.Tar/tests/TarFile/TarFile.CreateFromDirectoryAsync.Stream.Tests.cs	Added async tests for invalid format validation and format-specific archive creation
src/libraries/System.Formats.Tar/tests/TarFile/TarFile.CreateFromDirectoryAsync.File.Tests.cs	Added async tests for invalid format validation and format-specific archive creation

[Copilot]

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.

[alinpahontu2912]

LGTM 👍

[stephentoub]

Is this validation necessary, or will it be handled implicitly by the underlying TarWriter?

[iremyux]

Yes, TarWriter already validates the format, I added so it fails early. But yes, it is redundant

[iremyux]

Closing since it's a duplicate of #123407