Issue Link 🔗

#3965

Goals ⚽

Enhance AFError.url property to extract URL information from all applicable error types, improving debugging and error tracking capabilities. Previously only supported multipart encoding failures.

Implementation Details 🚧

Core Changes:

• Extended AFError.url to support 17 different error types through comprehensive switch statement
• Added extractURL(from:) helper method for consistent URL extraction from nested errors
• Enhanced documentation with detailed URL extraction behavior per error type

Supported Error Types:

• Nested errors: .multipartEncodingFailed, .responseValidationFailed, .responseSerializationFailed delegate to reason's URL
• Network errors: .sessionTaskFailed, .sessionInvalidated, .requestAdaptationFailed, .requestRetryFailed extract from underlying URLError
• Creation errors: Return nil - use response.request?.url for request URL

Usage:

AF.request("https://invalid-url.example").responseData { response in
    switch response.result {
    case let .failure(error):
        if let failingURL = error.url {
            print("Request failed for URL: \(failingURL)")
        }
        
        // For .invalidURL errors, use .urlConvertible for original input
        if case .invalidURL = error, let original = error.urlConvertible {
            print("Invalid URL input: \(original)")
        }
    case .success: break
    }
}

Backward compatibility: Existing AFError.url behavior for multipart errors unchanged.

Testing Details 🔍

New Tests: 461 lines of comprehensive test cases in AFErrorURLExtractionTests

• ✅ URL extraction for all 17 AFError types
• ✅ Nested error delegation (validation, serialization, multipart)
• ✅ URLError extraction from network failures
• ✅ Edge cases and nil handling

Documentation: Added Usage.md section with examples and architectural notes.

Results: All tests pass, existing AFError functionality unaffected.