Linux fixes

[thinkpractice]

Hi @mattt ,

I'm sending this PR a little early, more of a heads-up, although the code and tests already build. @pedronahum and I are working to bring swift-huggingface to Linux. We made a lot of changes that we will detail below. Our main idea is bringing swift-huggingface (and hopefully swift-transformers later) to TaylorTorch. At this point in time we're still need to solve some issues on Linux, most notably:

• MockURLProtocol.swift doesn't build on swift > 6.1 (we're currently building TaylorTorch with swift 6.3)
• Migrating the TokenStorage classes to use gnome keyring on Ubuntu

also we need to still test the swift-huggingface on Linux, which we will hope to do some time later this week.

kind regards,

Tim

Add Linux Support

This PR adds full Linux compatibility to the swift-huggingface library.

Changes

Dependencies

• Added swift-crypto package for cross-platform cryptographic operations (replaces Apple-only CryptoKit)

New Files

• Sources/HuggingFace/Shared/URLSession+Linux.swift - Async wrappers for URLSession APIs (asyncData, asyncUpload, asyncDownload, asyncBytes) since Linux's FoundationNetworking lacks native async/await support
• Sources/HuggingFace/OAuth/TokenStorage.swift - Cross-platform token storage implementations:
  • FileTokenStorage - File-based storage at ~/.cache/huggingface/token.json
  • EnvironmentTokenStorage - Reads from HF_TOKEN environment variable
  • CompositeTokenStorage - Combines multiple storage backends

Modified Files

• Package.swift - Added swift-crypto dependency
• Sources/HuggingFace/OAuth/OAuthClient.swift - Replaced CryptoKit with Crypto, added #if canImport(FoundationNetworking) conditionals for network calls
• Sources/HuggingFace/OAuth/HuggingFaceAuthenticationManager.swift - Wrapped AuthenticationServices-specific code with #if canImport guards
• Sources/HuggingFace/Hub/Pagination.swift - Converted HTTPURLResponse extension to free functions (parseNextPageURL(from:)) for Linux compatibility
• Sources/HuggingFace/Hub/HubClient+Files.swift - Added Linux conditionals, MIME type fallback (since UniformTypeIdentifiers is unavailable), made resumeDownloadFile and DownloadProgressDelegate Apple-only
• Sources/HuggingFace/Shared/HTTPClient.swift - Added Linux conditionals for all network operations, buffered SSE parsing for streaming responses
• Sources/HuggingFace/Hub/File.swift - Removed unused CryptoKit import

Test Updates

• Added #if canImport(FoundationNetworking) imports to all test files
• PaginationTests.swift - Updated to use free function parseNextPageURL(from:)
• HuggingFaceAuthenticationManagerTests.swift - Guarded with #if canImport(AuthenticationServices) (Apple-only)
• MockURLProtocol.swift - Fixed Swift 6 sendability issue using nonisolated(unsafe)

Platform-Specific Features

Some features remain Apple-only due to platform limitations:

• HuggingFaceAuthenticationManager (requires AuthenticationServices)
• Keychain-based token storage
• Download resume capability
• Real-time streaming (Linux uses buffered approach)

Testing

• swift build ✅
• swift build --build-tests ✅
• swift test ✅ (Linux)

[mattt]

Hi @thinkpractice. Wow, this is exciting! Lemme take a some time to go over all of this. Aiming to have a review for you tomorrow.

[thinkpractice]

@mattt thanks! Looking forward 😄 And let me know should you have any questions!